APA (7th ed.) Citation

Boxer, C. R. (1973). The Portuguese seaborne empire, 1415-1825. Penguin Books.

Chicago Style (17th ed.) Citation

Boxer, C. R. The Portuguese Seaborne Empire, 1415-1825. London: Penguin Books, 1973.

MLA (8th ed.) Citation

Boxer, C. R. The Portuguese Seaborne Empire, 1415-1825. Penguin Books, 1973.

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