Quality Automotive Book Publishers - favourites?

[VelvetGreen]

Hi all. Looking to expand my knowledge of quality car book publishers and buy some more automotive books. I'm familiar with Porter Press, Veloce, and Palawan at the top end, but are there any publishing houses / book series on cars and automotive topics (which includes things like race car engineering and technical works) which you enjoy and would recommend? If there was anything in particular you've read and loved, please do mention it as I'd like to buy 3-4 new books to get stuck into. I have a particular like for 60s,70s sports car racing but absolutely anything interesting will do.

Thanks in advance!