Ross, C. S., & Ross, M. M. (1980). Practical mathematics: Teacher's edition. Benefic Press.
Cita Chicago (17th ed.)Ross, Charles S., i Mary M. Ross. Practical Mathematics: Teacher's Edition. Benefic Press, 1980.
Cita MLA (9th ed.)Ross, Charles S., i Mary M. Ross. Practical Mathematics: Teacher's Edition. Benefic Press, 1980.
Atenció: Aquestes cites poden no estar 100% correctes.