Willcutt, R. E., Spikell, M. A., & Greenes, C. E. (1974). Multibase activities. Creative Publications.
Cita Chicago (17th ed.)Willcutt, Robert E., Mark A. Spikell, i Carole E. Greenes. Multibase Activities. Palo Alto, Ca.: Creative Publications, 1974.
Cita MLA (8th ed.)Willcutt, Robert E., et al. Multibase Activities. Creative Publications, 1974.
Atenció: Aquestes cites poden no estar 100% correctes.