Tyler, J., Gee, R., & McClelland, P. (1992). Spelling puzzles. Usborne Pub.
Cita Chicago (17th ed.)Tyler, Jenny, Robyn Gee, i Peter McClelland. Spelling Puzzles. London: Usborne Pub, 1992.
Cita MLA (9th ed.)Tyler, Jenny, et al. Spelling Puzzles. Usborne Pub, 1992.
Atenció: Aquestes cites poden no estar 100% correctes.