These RSS Feed is search result of Google Books. Your RSS reader need to support JSON RSS.
JavaScript(en):
https://azu.github.io/book-rss/JavaScript-en.json
JavaScript(ja):
https://azu.github.io/book-rss/JavaScript-ja.json
TypeScript(en):
https://azu.github.io/book-rss/TypeScript-en.json
TypeScript(ja):
https://azu.github.io/book-rss/TypeScript-ja.json