APA (7th ed.) Citation

YAP, PANG, & BOSE. (1992). Fortress Singapore: The battlefield guide. Times Books International.

Chicago Style (17th ed.) Citation

YAP, PANG, and BOSE. Fortress Singapore: The Battlefield Guide. Singapore: Times Books International, 1992.

MLA (8th ed.) Citation

YAP, et al. Fortress Singapore: The Battlefield Guide. Times Books International, 1992.