APA

Karls J. M., Wandrei K. E., . (2003). PIE manual: person-in-environment system. Washington, D.C: NASW Press, National Association of Social Workers.

Chicago

Karls James M, Wandrei Karin Evon, . 2003. PIE manual: person-in-environment system. Washington, D.C: NASW Press, National Association of Social Workers.

Harvard

Karls J. M., Wandrei K. E., . (2003). PIE manual: person-in-environment system. Washington, D.C: NASW Press, National Association of Social Workers.

MLA

Karls James M, Wandrei Karin Evon, . PIE manual: person-in-environment system. Washington, D.C: NASW Press, National Association of Social Workers. 2003.