APA (7th ed.) Citation

Keene,Carolyn. (1992). The Mystery Of The 99 Steps. Harper Collins.

Chicago Style (17th ed.) Citation

Keene,Carolyn. The Mystery Of The 99 Steps. London: Harper Collins, 1992.

MLA (9th ed.) Citation

Keene,Carolyn. The Mystery Of The 99 Steps. Harper Collins, 1992.

Warning: These citations may not always be 100% accurate.