1. Aromatic structures in coal maceral extracts and kerogens;Allan,1981
2. Some chemical and geochemical studies on sporopollenin;Brooks,1971
3. Separation and properties of coal macerals;Dyrkacz,1981
4. Some numerical aspects of specificity and reproducibility;Eshuis,1977
5. An essay on the organic geochemistry of coal;Given,1984