Cita APA (7th ed.)

WILLIAMS, K. W. (1970). Arithmetic: A semiprogrammed text. Prentice-Hall.

Cita Chicago (17th ed.)

WILLIAMS, Keith W. Arithmetic: A Semiprogrammed Text. Englewood Cliffs, N.J: Prentice-Hall, 1970.

Cita MLA (9th ed.)

WILLIAMS, Keith W. Arithmetic: A Semiprogrammed Text. Prentice-Hall, 1970.