diff --git a/episodes/04-collaboration.md b/episodes/04-collaboration.md
index c2480204..26f4e80b 100644
--- a/episodes/04-collaboration.md
+++ b/episodes/04-collaboration.md
@@ -42,7 +42,7 @@ Discussion
 - What goes wrong with collaboration?
 - How can you prepare to collaborate?
 
-:::::::::::::::  solution
+:::::::::::::::::  spoiler
 
 ## Suggestions
 
diff --git a/episodes/05-project_organization.md b/episodes/05-project_organization.md
index d7333f51..6689ba80 100644
--- a/episodes/05-project_organization.md
+++ b/episodes/05-project_organization.md
@@ -249,8 +249,6 @@ For your information, to encode experimental details the following conventions w
 - measurement date
 - other details are timepoint and raw or normalized data
 
-:::::::::::::::  solution
-
 ```
 2020-07-14_s12_phyB_on_SD_t04.raw.csv  
 2020-07-14_s1_phyA_on_LD_t05.raw.csv  
@@ -272,8 +270,6 @@ SD_phya_ons_t04_2020-07-12.norm.csv
 ld_phyA_ons_t04_2020-08-12.norm.csv  
 ```
 
-:::::::::::::::::::::::::
-
 - What are the problems with having the date first?
 - How do different date formats behave once sorted?
 - Can you tell the importance of a leading 0 (zeros)?
@@ -282,21 +278,27 @@ ld_phyA_ons_t04_2020-08-12.norm.csv
 - Do you see benefits of keeping consistent lengths of the naming conventions?
 - Do you see what happens when you mix conventions?
 
-> ## Solution
-> 
-> - Using dates up front makes it difficult to quickly find data for
->   particular conditions or genotypes. It also masks the "logical" order of samples
->   or timepoints.
-> - Named months break the "expected" sorting, same as dates without leading 0
-> - Without leading zeros, 's12' appear before s1 and s2
-> - the first (and second) part of the name are easiest to spot
-> - the last file is also from LD conditions, but appears after SD, same with 'phya' genotypes
-> - the last 3 file names are easiest to read as all parts appear on top of each other
->   due to the same 3 letter-length codes ons and off
-> - The lack of consistency makes it very difficult to get data from related samples/conditions.
+::::::::::::::::::::::::: solution
+
+
+
+## Solution
+
+ - Using dates up front makes it difficult to quickly find data for
+   particular conditions or genotypes. It also masks the "logical" order of samples
+   or timepoints.
+ - Named months break the "expected" sorting, same as dates without leading 0
+ - Without leading zeros, 's12' appear before s1 and s2
+ - the first (and second) part of the name are easiest to spot
+ - the last file is also from LD conditions, but appears after SD, same with 'phya' genotypes
+ - the last 3 file names are easiest to read as all parts appear on top of each other
+   due to the same 3 letter-length codes ons and off
+ - The lack of consistency makes it very difficult to get data from related samples/conditions.
 
 ::::::::::::::::::::::::::::::::::::::::::::::::::
 
+:::::::::::::::::::::::::::
+
 :::::::::::::::::::::::::::::::::::::::::  callout
 
 ## Some helpful organisation tools
@@ -318,7 +320,7 @@ ld_phyA_ons_t04_2020-08-12.norm.csv
 ## Attribution
 
 This episode was adapted from and includes material from Wilson et al.
-[Good Enough Practices for Scientific Computing](https://github.com/swcarpentry/good-enough-practices-in-scientific-computing).
+[Good Enough Practices for Scientific Computing](https://doi.org/10.1371/journal.pcbi.1005510).
 
 Some content was adapted from [FAIR in Biological Practice episode on files and organisation](https://carpentries-incubator.github.io/fair-bio-practice/09-files-organization/index.html). That material gives a slightly different and also useful perspective.