Cita APA (7a ed.)

Erlinghagen, M., & Hank, K. (2006). The participation of older Europeans in volunteer work. [s.n.].

Cita Chicago Style (17a ed.)

Erlinghagen, Marcel, y Karsten Hank. The Participation of Older Europeans in Volunteer Work. [S.l.]: [s.n.], 2006.

Cita MLA (9a ed.)

Erlinghagen, Marcel, y Karsten Hank. The Participation of Older Europeans in Volunteer Work. [s.n.], 2006.