Cutler, Ann.
The Trachtenberg speed system of basic mathematics / translated and adapted by Ann Cutler and Rudolph McShane. - London : Souvenir, c1960. - 270 p. : ill.
Trachtenberg, Jakow, 1888-
Arithmetic.
The Trachtenberg speed system of basic mathematics / translated and adapted by Ann Cutler and Rudolph McShane. - London : Souvenir, c1960. - 270 p. : ill.
Trachtenberg, Jakow, 1888-
Arithmetic.