Cita APA (7a ed.)

Spann, O., Paul, E., & Paul, C. (1930). Types of economic theory. George Allen & Unwin.

Cita Chicago Style (17a ed.)

Spann, Othmar, Eden Paul, y Cedar Paul. Types of Economic Theory. London: George Allen & Unwin, 1930.

Cita MLA (9a ed.)

Spann, Othmar, et al. Types of Economic Theory. George Allen & Unwin, 1930.