diff --git a/content/notes/think-writing.md b/content/notes/think-writing.md
index cdb392e85..81f605f44 100644
--- a/content/notes/think-writing.md
+++ b/content/notes/think-writing.md
@@ -36,4 +36,11 @@ So within a supply chain blockchain, each change in the state of an item is reco
 
 From the bitcoin whitepaper: ![](https://i.imgur.com/VutNw5Y.png) Do closed blockchains look the same?
 
-https://www.hyperledger.org/wp-content/uploads/2018/08/HL_Whitepaper_IntroductiontoHyperledger.pdf
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+https://www.hyperledger.org/wp-content/uploads/2018/08/HL_Whitepaper_IntroductiontoHyperledger.pdf
+- Different services within hyperledger
+	- fabric
+	- indy
+	- explore
+	- sawtooth
+	- grid
+	- aries
\ No newline at end of file