diff --git a/README.md b/README.md
index e67635b5..9c7a36ae 100644
--- a/README.md
+++ b/README.md
@@ -147,9 +147,11 @@ Primitive values are directly assigned to a variable, and when you manipulate a
 ### Reference
 
 -  [JavaScript data types and data structures — MDN](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Primitive_values)
+-  [Know more about ECMAScript (in detail)](https://262.ecma-international.org/)
 
 ### <img  align= center width=40px height=40px src="https://cdn-icons-png.flaticon.com/512/1945/1945940.png"> Articles
 
+-  [Introduction to ECMAScript (ES6) - GeeksforGeeks](https://www.geeksforgeeks.org/introduction-to-es6/)
 -  [Primitive and Non-primitive data-types in JavaScript - GeeksforGeeks](https://www.geeksforgeeks.org/primitive-and-non-primitive-data-types-in-javascript)
 -  [Javascript variables (Beginner thinking)](https://robiul.dev/javascript-variables-beginner-thinking)
 -  [How numbers are encoded in JavaScript — Dr. Axel Rauschmayer](http://2ality.com/2012/04/number-encoding.html)
@@ -990,6 +992,8 @@ The Event Loop is a critical part of JavaScript’s concurrency model, ensuring
 -  [Promise Basics - javascript.info](https://javascript.info/promise-basics)
 -  [The Complete JavaScript Promise Guide](https://blog.webdevsimplified.com/2021-09/javascript-promises)
 -  [Promise Chaining - javascript.info](https://javascript.info/promise-chaining)
+-  [Promise vs Observables(subscribe)](https://www.stackchief.com/tutorials/JavaScript%20Observables%20in%205%20Minutes)
+
 
 ### <img align=center width="40" height="40" src="https://img.icons8.com/dusk/64/video.png" alt="video"/>  Videos