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2. Chemical structure and properties of coal. XVIII. Oxygen groups in coal and related products;Blom;Fuel,1957
3. Petroleum origin;Brooks,1953
4. La transformation du pétrole brut dans la nature;Dobryansky;Rev. Inst. Français Petrole,1963
5. Sui minerali argillosi a strati misti presenti nelle argillo nere triassiche delia Sicilia sud-orientale;Favretto;Rend. Soc. Miner. Italiana,1965