Παραπομπή APA

Isard, W., Langford, T. W., & Romanoff, E. Philadelphia region input-output study. Philadelphia, PA: Regional Science Research Institute.

Παραπομπή Chicago Style

Isard, Walter, Thomas W. Langford, and Eliahu Romanoff. Philadelphia Region Input-output Study. Philadelphia, PA: Regional Science Research Institute.

Παραπομπή MLA

Isard, Walter, Thomas W. Langford, and Eliahu Romanoff. Philadelphia Region Input-output Study. Philadelphia, PA: Regional Science Research Institute.

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