Cita APA (7a ed.)

Sommerfelt, A., & Marm, I. (1978). Norwegian: A book of self-instruction in the Norwegian riksmal : [a practical course for beginners and students] (1st., 9th imp.). Hodder and Stoughton.

Cita Chicago Style (17a ed.)

Sommerfelt, Alf, y Ingvald Marm. Norwegian: A Book of Self-instruction in the Norwegian Riksmal : [a Practical Course for Beginners and Students]. 1st., 9th imp. London [etc.]: Hodder and Stoughton, 1978.

Cita MLA (9a ed.)

Sommerfelt, Alf, y Ingvald Marm. Norwegian: A Book of Self-instruction in the Norwegian Riksmal : [a Practical Course for Beginners and Students]. 1st., 9th imp. Hodder and Stoughton, 1978.