diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index 8b27a3d3a85d5cdb59636b5afddae6e16ac9a368..adcfaaed014056e878674a1fa2b3aefad4b9457c 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -8,9 +8,7 @@
 
 ## Supplementary exercices
 - Add summary of all code used in the session at the end of the sesssion
-- Write the session_1/bioconductor.Rmd training (and add link in session_1.Rmd)
-- Write the session_1/github.Rmd training (and add link in session_1.Rmd)
 - Write the WDI.Rmd training which will be for a later session
 - Write tuto to create IFB accout and launch Rstudio server
 - Write session_2/exel.Rmd to load an exel version of the mpg data
-- Write session_2/ggannimate.Rmd https://exts.ggplot2.tidyverse.org/gallery/ or another example of ggplot2 addons
\ No newline at end of file
+- Write session_2/ggannimate.Rmd https://exts.ggplot2.tidyverse.org/gallery/ or another example of ggplot2 addons and cowplot (https://wilkelab.org/cowplot/articles/introduction.html)
\ No newline at end of file