diff --git a/README.md b/README.md
index 9075651..c755a25 100644
--- a/README.md
+++ b/README.md
@@ -5,3 +5,7 @@ Contains lists of things to know/remember in different topics.
 , it was used and created during the creation of the BOK token smart contract. See SafeUpgradeableTokenERC20 contract implementation here: https://github.com/guylando/EthereumSmartContracts
 
 2. Many information security lists which I will later move to this github repository appear in my blog here: https://secinfodb.wordpress.com/
+
+https://solidity-by-example.org/hacks/deploy-different-contracts-same-address/
+https://medium.com/coinmonks/math-in-solidity-part-3-percents-and-proportions-4db014e080b1
+https://consensys.github.io/smart-contract-best-practices/