Παραπομπή APA

(1970). County business patterns 1969: Pennslylvania. Washington, DC: Government Printing Office.

Παραπομπή Chicago Style

County Business Patterns 1969: Pennslylvania. Washington, DC: Government Printing Office, 1970.

Παραπομπή MLA

County Business Patterns 1969: Pennslylvania. Washington, DC: Government Printing Office, 1970.

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