[yantrams]

This one is new to me. I still have my copies of Physics for Entertainment and Mathematics can be fun by the same author - Yakov Perelman. I owe my superfast stereogram decoding skills ( < 2 seconds most of the times ) to him :)

Here's an interesting tidbit from his wikipedia page - He is not related to the Russian mathematician Grigori Perelman, who was born in 1966 to a different Yakov Perelman. However, Grigori Perelman told The New Yorker that his father gave him Physics for Entertainment, and it inspired his interest in mathematics

[__rito__]

The book is no more. It has been taken down, and I cannot find it anywhere.

Could you kindly email it to me? I will be grateful.