Não informado. (1974). Quarry management and products. Quarry Managers Journal.
Παραπομπή σε μορφή Chicago (17η εκδ.)Não informado. Quarry Management and Products. London: Quarry Managers Journal, 1974.
Παραπομπή σε μορφή MLA (8th εκδ.)Não informado. Quarry Management and Products. Quarry Managers Journal, 1974.
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