APA

Karls J. M., Wandrei K. E. & National Association of Social Workers. (1994). PIE manual: person-in-environment system. Washington, D.C: NASW Press, National Association of Social Workers.

Chicago

Karls James M, Wandrei Karin Evon and National Association of Social Workers. 1994. PIE manual: person-in-environment system. Washington, D.C: NASW Press, National Association of Social Workers.

Harvard

Karls J. M., Wandrei K. E. and National Association of Social Workers. (1994). PIE manual: person-in-environment system. Washington, D.C: NASW Press, National Association of Social Workers.

MLA

Karls James M, Wandrei Karin Evon and National Association of Social Workers. PIE manual: person-in-environment system. Washington, D.C: NASW Press, National Association of Social Workers. 1994.