Single Comment

Gollon's 'Chess Variations' is informative and provides a decent tour of
the subject, including (if memory serves) such historical variants as
Byzantine Chess and Chaturanga, as well as Capablanca's Chess.

It's disappointing to learn that it recently went out of print;
discovering and reading 'Chess Variations' is what revived my interest
in chess variants as an adult.  If you can't find it in your library,
perhaps your librarian can get it via inter-library loan. A much-used copy
of this book was available in the Minot, North Dakota, public library as
of 1997, when I last visited that area.