International Labor Office, Berthelot, M, International Labor Office, International Labor Office, International Labor Office, International Labor Office, . . . Lazard, M. (1975). Coal production in the Ruhr district (end of May 1920): Enquiry by the International Labour Office. Nendehln, Kraus Reprint.
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्रInternational Labor Office, et al. Coal Production in the Ruhr District (end of May 1920): Enquiry by the International Labour Office. [Geneva]: Nendehln, Kraus Reprint, 1975.
एमएलए (9वां संस्करण) प्रशस्ति पत्रInternational Labor Office, et al. Coal Production in the Ruhr District (end of May 1920): Enquiry by the International Labour Office. Nendehln, Kraus Reprint, 1975.
चेतावनी: ये उद्धरण हमेशा 100% सटीक नहीं हो सकते हैं.