[amativos]

Late reply, but Gelfand's geometry textbook was published [0] in 2020. I think it was completed by his colleagues after his death in 2009. The calculus [1] and combinatorics [2] books are also in print.

[0] https://www.springer.com/gp/book/9781071602973

[1] https://store.doverpublications.com/0486414485.html

[2] https://store.doverpublications.com/0486425665.html

[kjander79]

Thank you for pointing me to these.