Francis, M., & Knight, C. (1987). Cumulus. Parkett.
Cita Chicago (17th ed.)Francis, Mark, i Christopher Knight. "Cumulus." Parkett 1987.
Cita MLA (8th ed.)Francis, Mark, i Christopher Knight. "Cumulus." Parkett, 1987.
Atenció: Aquestes cites poden no estar 100% correctes.