APA-referens (7:e uppl.)

Penjerdel (Corporation). (1961). Historical development of local government in the Penjerdel region. Pennsylvania Economy League (Eastern Division).

Chicago-referens (17:e uppl.)

Penjerdel (Corporation). Historical Development of Local Government in the Penjerdel Region. Philadelphia?: Pennsylvania Economy League (Eastern Division), 1961.

MLA-referens (8:e uppl.)

Penjerdel (Corporation). Historical Development of Local Government in the Penjerdel Region. Pennsylvania Economy League (Eastern Division), 1961.