diff --git a/topics/qalg.md b/topics/qalg.md
index 54035e3..e8088be 100644
--- a/topics/qalg.md
+++ b/topics/qalg.md
@@ -3,6 +3,7 @@
 - [Quantum Algorithm Zoo](https://quantumalgorithmzoo.org/)
 
 - [Yao](https://yaoquantum.org/): Extensible, Efficient Quantum Algorithm Design For Humans
-- 
+- [arxiv][A Quantum Approximate Optimization Algorithm](https://arxiv.org/abs/1411.4028)
+- [natrue review][Variational quantum algorithms](https://doi.org/10.1038/s42254-021-00348-9)
 
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+###