Cita APA

Olsen, O., & Olsen, E. (2010). Fresh air in dark places (1. edition.). Scotland, UK: Witherby Seamanship International.

Citación estilo Chicago

Olsen, Olaf, y Erik Olsen. Fresh Air in Dark Places. 1. edition. Scotland, UK: Witherby Seamanship International, 2010.

Cita MLA

Olsen, Olaf, y Erik Olsen. Fresh Air in Dark Places. 1. edition. Scotland, UK: Witherby Seamanship International, 2010.