Cita APA (7a ed.)

Petri, B., Wagner, E., & Wilhelm, S. (1998). memo 38.

Cita Chicago Style (17a ed.)

Petri, Barbara, Ellen Wagner, y Susanne Wilhelm. Memo 38. Wiesbaden, 1998.

Cita MLA (8a ed.)

Petri, Barbara, et al. Memo 38. 1998.