diff --git a/README.md b/README.md
index 50eca05889b3..227ba324ba35 100644
--- a/README.md
+++ b/README.md
@@ -641,6 +641,7 @@ Here are some companies/projects (alphabetical order) using OpenAPI Generator in
 - 2019-09-14 - [Generating and Configuring a Mastercard API Client](https://developer.mastercard.com/platform/documentation/generating-and-configuring-a-mastercard-api-client/) at [Mastercard Developers Platform](https://developer.mastercard.com/platform/documentation/)
 - 2019-09-15 - [OpenAPI(Swagger)導入下調べ](https://qiita.com/ShoichiKuraoka/items/f1f7a3c2376f7cd9c56a) by [Shoichi Kuraoka](https://qiita.com/ShoichiKuraoka)
 - 2019-09-22 - [OpenAPI 3を完全に理解できる本](https://booth.pm/ja/items/1571902) by [@ota42y](https://twitter.com/ota42y)
+- 2019-09-22 - [RESTful APIs: Tutorial of OpenAPI Specification](https://medium.com/@amirm.lavasani/restful-apis-tutorial-of-openapi-specification-eeada0e3901d) by [Amir Lavasani](https://medium.com/@amirm.lavasani)
 - 2019-09-23 - [swaggerからOpenApi GeneratorでSpringのコードを自動生成](https://qiita.com/littleFeet/items/492df2ad68a0799a5e5e) by [@littleFeet](https://qiita.com/littleFeet) at [Qiita](https://qiita.com/)