diff --git a/10-data-transformation.md b/10-data-transformation.md
old mode 100755
new mode 100644
diff --git a/11-using-arrays-transformations.md b/11-using-arrays-transformations.md
index 625e2344..746eb3a4 100644
--- a/11-using-arrays-transformations.md
+++ b/11-using-arrays-transformations.md
@@ -62,8 +62,7 @@ Arrays can be sorted, de-duplicated, and manipulated in other ways in GREL expre
 
 `"crystal structure|clozapinium|crystal structure|molecular configuration|hydrogen bonding|supramolecular assembly|Chemistry|QD1-999"`
 
-This can be transformed into an array using the `split` function specifying the pipe character ( | ) as the separating character. Recall the cautionary note about separator choice from [Working with Data](https://librarycarpentry.org/lc-open-refine/03-working-with-data/index.html).
-.
+This can be transformed into an array using the `split` function specifying the pipe character ( | ) as the separating character. Recall the cautionary note about separator choice from [Working with Data](03-working-with-data.md#choosing-a-good-separator).
 
 ```
 value.split("|")
diff --git a/md5sum.txt b/md5sum.txt
index 1a58df8d..2134dc6c 100644
--- a/md5sum.txt
+++ b/md5sum.txt
@@ -13,7 +13,7 @@
 "episodes/08-writing-transformations.md" "b69d3a52f8de4655d7c8695d95d5821d" "site/built/08-writing-transformations.md" "2023-05-01"
 "episodes/09-undo-and-redo.md" "9dba6d90cc6d8d9d5381cb537006b63e" "site/built/09-undo-and-redo.md" "2023-05-01"
 "episodes/10-data-transformation.md" "47399b9f87a7c2dfae1d6b67eea71cc7" "site/built/10-data-transformation.md" "2023-05-26"
-"episodes/11-using-arrays-transformations.md" "0a72814d1256acbed6a6113a741317c6" "site/built/11-using-arrays-transformations.md" "2023-06-27"
+"episodes/11-using-arrays-transformations.md" "e115138dcb3c916bcaf5634600e594c4" "site/built/11-using-arrays-transformations.md" "2023-12-15"
 "episodes/12-export-transformation.md" "aa6dd576a893a0870baa24611573e50b" "site/built/12-export-transformation.md" "2023-05-01"
 "episodes/13-looking-up-data.md" "4be5191800691af09ff34b5fdd4c05bd" "site/built/13-looking-up-data.md" "2023-11-22"
 "instructors/instructor-notes.md" "c2dfd88f1e85cccb9cbe872530c534ac" "site/built/instructor-notes.md" "2023-11-21"