Update README.md

README.md

@@ -88,7 +88,13 @@ This is an UNOFFICIAL release of the [RNAcentral](https://rnacentral.org) by The
 
 - **Homepage:** https://rnacentral.org
 - **Documentation:** https://multimolecule.danling.org/datasets/rnacentral
-- **Paper:** [RNAcentral: a hub of information for non-coding RNA sequences](https://doi.org/10.1093/nar/gky1034)
+- **Papers:**
+  - [RNAcentral 2021: secondary structure integration, improved sequence search and new member databases](https://doi.org/10.1093/nar/gkaa921)
+  - [Exploring Non-Coding RNAs in RNAcentral](https://doi.org/10.1002/cpbi.104)
+  - [RNAcentral: a hub of information for non-coding RNA sequences](https://doi.org/10.1093/nar/gky1034)
+  - [RNAcentral: a comprehensive database of non-coding {RNA} sequences](https://doi.org/10.1093/nar/gkw1008)
+  - [RNAcentral: an international database of ncRNA sequences](https://doi.org/10.1093/nar/gku991)
+  - [RNAcentral: A vision for an international database of RNA sequences](https://doi.org/10.1261/rna.2750811)
 - **Point of Contact:** [Blake Sweeney](https://www.ebi.ac.uk/people/person/blake-sweeney/)
 
 ## License