APA (7th ed.) Citation

Johnston, G., & Johnston, B. (1980). This is Hongkong, butterflies. Information Services.

Chicago Style (17th ed.) Citation

Johnston, Gweneth, and Bernard Johnston. This Is Hongkong, Butterflies. Hongkong: Information Services, 1980.

MLA (9th ed.) Citation

Johnston, Gweneth, and Bernard Johnston. This Is Hongkong, Butterflies. Information Services, 1980.

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