What has the author R L Sarkar written?

There seems to be some confusion. There is no widely recognized author named "R L Sarkar." It's possible you're thinking of a different name or there's a typo.

Could you please double-check the spelling or provide more context? For example:

* Is there a specific book or genre you're interested in?

* Do you have any other information about the author?

Once I have more information, I'll be able to assist you better.