1. 13C NMR studies of solid coal samples;Batuska,1976
2. High resolution mass spectrometry of Green River formation kerogen oxidation;Burlingame;Nature,1969
3. Chemical constitution of coal XII—optimum conditions for the preparation of subhumic acids from humic acids by oxidation withalkaline potassium permanganate;Davies;Fuel,1962
4. Organic acids obtained by alkaline permanganate oxidation of kerogen from the Green River (Colorado) shale;Djuricic;Geochim. Cosmochim. Acta,1971
5. Acids obtained by oxidation of kerogens of ancient sediments of different geographic origin;Djuricic,1972