diff --git a/advanced_expert/vulnerabilities/ddos.md b/advanced_expert/vulnerabilities/ddos.md
deleted file mode 100644
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--- a/advanced_expert/vulnerabilities/ddos.md
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-## DDoS attacks on the context of blockchains
-
-<br>
-
-### Failed Call
-
-<br>
-
-* [DDoS with Failed Call](https://swcregistry.io/docs/SWC-113)
-
-
-<br>
-
-### Block gas limit
-
-<br>
-
-* [Block gas limit by SWC registry](https://swcregistry.io/docs/SWC-128)
-* [Gas limit and loops on Solidity docs](https://docs.soliditylang.org/en/latest/security-considerations.html#gas-limit-and-loops)
-* [External Calls without Gas Stipends]()
-
-
-<br>
-
-### Learning references
-
-<br>
-
-* [Sigma Prime post](https://blog.sigmaprime.io/solidity-security.html#dos)
-* [Not so smart contract](https://github.com/crytic/not-so-smart-contracts/tree/master/denial_of_service)
diff --git a/advanced_expert/vulnerabilities/ddos/README.md. b/advanced_expert/vulnerabilities/ddos/README.md.
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+++ b/advanced_expert/vulnerabilities/ddos/README.md.
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+## DDoS attacks on the context of blockchains
+
+<br>
+
+### failed call
+
+<br>
+
+* [DDoS with failed call](https://swcregistry.io/docs/SWC-113)
+
+
+<br>
+
+### block gas limit
+
+<br>
+
+* [block gas limit by SWC registry](https://swcregistry.io/docs/SWC-128)
+* [gas limit and loops on solidity docs](https://docs.soliditylang.org/en/latest/security-considerations.html#gas-limit-and-loops)
+
+
+
+<br>
+
+### references
+
+<br>
+
+* [sigma prime post](https://blog.sigmaprime.io/solidity-security.html#dos)
+* [not so smart contract](https://github.com/crytic/not-so-smart-contracts/tree/master/denial_of_service)