diff --git a/Notebooks/Unix/basic/basic.ipynb b/Notebooks/Unix/basic/basic.ipynb
index 589099e..467e4bd 100644
--- a/Notebooks/Unix/basic/basic.ipynb
+++ b/Notebooks/Unix/basic/basic.ipynb
@@ -241,7 +241,7 @@
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "#### Tab completion\n",
+    "## Tab completion\n",
     "\n",
     "Typing out file names is really boring and you're likely to make typos which will at best make your command fail with a strange error and at worst overwrite some of your carefully crafted analysis.  _Tab completion_ is a trick which normally reduces this risk significantly.\n",
     "\n",
diff --git a/Notebooks/Unix/cheat_sheet/unix_cheat_sheet.ipynb b/Notebooks/Unix/cheat_sheet/unix_cheat_sheet.ipynb
index ade0f92..454890a 100644
--- a/Notebooks/Unix/cheat_sheet/unix_cheat_sheet.ipynb
+++ b/Notebooks/Unix/cheat_sheet/unix_cheat_sheet.ipynb
@@ -13,7 +13,8 @@
     "ls # What else is in this directory\n",
     "ls .. # What is in the directory above me\n",
     "ls foo/bar/ # What is inside the bar directory which is inside the foo/ directory\n",
-    "ls -lah foo/ # Give the the details (-l) of all files and folders (-a) using human readable file sizes (-h)\n",
+    "ls -lah foo/ # Give the the details (-l) of all files and folders (-a) using human\n",
+    "             # readable file sizes (-h)\n",
     "cd ../.. # Move up two directories\n",
     "cd ../foo/bar # Move up one directory and down into the foo/bar/ subdirectories\n",
     "cp -r foo/ baz/ # Copy the foo/ directory into the baz/ directory\n",
@@ -26,7 +27,8 @@
     "\n",
     "```\n",
     "less bar.bed # scroll through bar.bed\n",
-    "grep chrom bar.bed | less -S # Only look at lines in bar.bed which have 'chrom' and don't wrap lines (`-S`)\n",
+    "grep chrom bar.bed | less -S # Only look at lines in bar.bed which have 'chrom' and\n",
+    "                             # don't wrap lines (-S)\n",
     "head -20 bar.bed # show me the first 20 lines of bar.bed\n",
     "tail -20 bar.bed # show me the last 20 lines\n",
     "cat bar.bed # show me all of the lines (bad for big files)\n",
@@ -43,7 +45,8 @@
     "grep -r foo baz/ # show me all examples of foo in baz/ and every subdirectory within it\n",
     "grep '^foo' bar.bed # show me all of the lines begining with foo\n",
     "grep 'foo$' bar.bed # show me all of the lines ending in foo\n",
-    "grep -i '^[acgt]$' bar.bed # show me all of the lines which only have the characters a,c,g and t (ignoring their case)\n",
+    "grep -i '^[acgt]$' bar.bed # show me all of the lines which only have the characters\n",
+    "                           # a,c,g and t (ignoring their case)\n",
     "grep -v foo bar.bed # don't show me any files with foo in them\n",
     "```\n",
     "\n",
@@ -56,7 +59,9 @@
     "awk -F\"\\t\" '{print $NF}' bar.bed # ignore spaces and print the last column\n",
     "awk -F\"\\t\" '{print $(NF-1)}' bar.bed # print the penultimate column\n",
     "awk '{sum+=$2} END {print sum}' bar.bed # print the sum of the second column\n",
-    "awk '/^foo/ {sum+=$2; count+=1} END {print sum/count}' bar.bed # print the average of the second value of lines starting with foo\n",
+    "awk '/^foo/ {sum+=$2; count+=1} END {print sum/count}' bar.bed # print the average of the\n",
+    "                                                               # second value of lines starting\n",
+    "                                                               # with foo\n",
     "```\n",
     "\n",
     "## Piping, redirection and more advanced queries\n",
@@ -74,7 +79,7 @@
     "# awk => NR: is the row number\n",
     "#        NR%10: is the modulo (remander) of dividing my 10\n",
     "#        awk is therefore giving you every 10th line\n",
-    "# head => only show the first 20    \n",
+    "# head => only show the first 20\n",
     "\n",
     "awk '{l=($3-$2+1)}; (l<300 && $2>200000 && $3<250000)' exercises.bed\n",
     "# Gives:\n",
@@ -122,7 +127,8 @@
     "  exit 2\n",
     "fi\n",
     "\n",
-    "# Get the lines which aren't headers, take the first column and return the unique values\n",
+    "# Get the lines which aren't headers,\n",
+    "# take the first column and return the unique values\n",
     "number_of_contigs_in_one=$(awk '$1 !~ /^#/ {print $1}' $file_one | sort -u | wc -l)\n",
     "number_of_contigs_in_two=$(awk '/^[^#]/ {print $1}' $file_two | sort -u | wc -l)\n",
     "\n",
@@ -151,7 +157,7 @@
     "* `man the_name_of_a_command` often gives you help\n",
     "* Google is normally better at giving examples (prioritise stackoverflow.com results, they're normally good)\n",
     "\n",
-    "#### Build commands slowly\n",
+    "## Build commands slowly\n",
     "\n",
     "If you wanted me to calculate the sum of all of the scores for genes on contig-1 in a bed file, I'd probably run each of the following commands before moving onto the next:\n",
     "\n",
@@ -161,25 +167,32 @@
     "awk '{print $1}' bar.bed | sort -u | less # check the contigs don't look wierd\n",
     "awk '{print $4}' bar.bed | sort -u | less # check the genes don't look wierd\n",
     "awk '$4 ~ /gene-/' bar.bed | head -20 # check that I can spot genes\n",
-    "awk '($1 == \"contig-1\" && $4 ~ /gene-/)' bar.bed | head -20 # check I can find genes on contig-1\n",
-    "head -20 bar.bed | awk '($1 == \"contig-1\" && $4 ~ /gene-/) {sum+=$5}; END {print sum}' # check my maths\n",
-    "awk '($1 == \"contig-1\" && $4 ~ /gene-/) {sum+=$5}; END {print sum}' bar.bed # get the answer you actually want\n",
+    "awk '($1 == \"contig-1\" && $4 ~ /gene-/)' bar.bed | head -20 # check I can find\n",
+    "                                                            # genes on contig-1\n",
+    "# check my algorithm works on a subset of the data\n",
+    "head -20 bar.bed | awk '($1 == \"contig-1\" && $4 ~ /gene-/) {sum+=$5}; END {print sum}'\n",
+    "# apply the algorithm to all of the data\n",
+    "awk '($1 == \"contig-1\" && $4 ~ /gene-/) {sum+=$5}; END {print sum}' bar.bed\n",
     "```\n",
     "\n",
     "## Which tool should I use?\n",
     "\n",
     "You should probably use awk if:\n",
+    "\n",
     "* your data has columns\n",
     "* you need to do simple maths\n",
     "\n",
     "You should probable use grep if:\n",
+    "\n",
     "* you're looking for files which contain some specific text (e.g. `grep -r foo bar/`: look in all the files in `bar/` for any with the word 'foo')\n",
     "\n",
     "You should use find if:\n",
+    "\n",
     "* you know something about a file (like it's name or creation date) but not where it is\n",
     "* you want a list of all the files in a subdirectory and its subdirectories etc.\n",
     "\n",
     "You should write a script if:\n",
+    "\n",
     "* your code doesn't fit on one line\n",
     "* it's doing something you might want to do again in 3 months\n",
     "* you want someone else to be able to do it without asking loads of questions\n",
@@ -187,6 +200,7 @@
     "* you're doing something lots of times\n",
     "\n",
     "You should probably use less or head:\n",
+    "\n",
     "* always, you should always use less or head to check intermediary steps in your analysis\n"
    ]
   }