Krevelen, D. W. v. (1993). Coal: Typology-physics-chemistry-constitution (3rd ed., completely revised.). Amsterdam: Elsevier Publishing Co..
Παραπομπή Chicago StyleKrevelen, D. W. van. Coal: Typology-physics-chemistry-constitution. 3rd ed., completely revised. Amsterdam: Elsevier Publishing Co., 1993.
Παραπομπή MLAKrevelen, D. W. van. Coal: Typology-physics-chemistry-constitution. 3rd ed., completely revised. Amsterdam: Elsevier Publishing Co., 1993.
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