Cita APA (7a ed.)

Haugen, E. I. (1950). Problems of bilingualism. [s.n.].

Cita Chicago Style (17a ed.)

Haugen, Einar Ingvald. Problems of Bilingualism. [S.l.]: [s.n.], 1950.

Cita MLA (9a ed.)

Haugen, Einar Ingvald. Problems of Bilingualism. [s.n.], 1950.