Penjerdel (Corporation). (1961). Historical development of local government in the Penjerdel region. Pennsylvania Economy League (Eastern Division).
Chicago-viite (17. p.)Penjerdel (Corporation). Historical Development of Local Government in the Penjerdel Region. Philadelphia?: Pennsylvania Economy League (Eastern Division), 1961.
MLA-viite (8. p.)Penjerdel (Corporation). Historical Development of Local Government in the Penjerdel Region. Pennsylvania Economy League (Eastern Division), 1961.
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