APA

Ropers R. H., . (1991). Persistent poverty. New York [u.a.]: Plenum Press.

Chicago

Ropers Richard H, . 1991. Persistent poverty. New York [u.a.]: Plenum Press.

Harvard

Ropers R. H., . (1991). Persistent poverty. New York [u.a.]: Plenum Press.

MLA

Ropers Richard H, . Persistent poverty. New York [u.a.]: Plenum Press. 1991.