Many web programmers, especially Angular programmers are turning their attention to
Reactive programming. While I don’t know of any books on ReactiveJS (yet) I can shamelessly mention that I do have a book on Reactive Extensions and LINQ.
NB: This book is short (which I think is a good thing) and pricey, but will give you a solid introduction and more to both topics.
My co-author, Paul Betts, is not only a genius, but he is one of the foremost experts on Reactive.
Here is the TOC:

About Jesse Liberty
Jesse Liberty has three decades of experience writing and delivering software projects and is the author of 2 dozen books and a couple dozen online courses.
His latest book, Building APIs with .NET, is now available wherever you buy your books.
Liberty is a Senior SW Engineer for CNH and he was a Senior Technical Evangelist for Microsoft, a Distinguished Software Engineer for AT&T, a VP for Information Services for Citibank and a Software Architect for PBS. He is a Microsoft MVP.
I believe there are many more pleasurable opportunities ahead for individuals that looked at your site. We are providing AngularJs trining in velachery.
For more details visit us at: http://www.zerobugacademy.com/angularjs-training-in-chennai
Jesse, I bought this book when it was first published and it’s an excellent read. Looking forward to it coming back!