1. Blix, G.: The determination of hexosamine according to Elson and Morgan. Acta chem. scand. 2, 467–474 (1948).
2. Dobiás, J.: Bronchiálni zmĕny při pneumokonióze. Pracov. Lék. 20, 210–214 (1968).
3. Heppleston, H. G.: Coal workers’ pneumoconiosis. Pathological and etiological consideration. Arch. industr. Hyg. 4, 270–288 (1951).
4. King, E. J., Maguire, B. A., Nagelschmidt, G.: Further studies of the dust in lungs of coal-miners. Brit. J. industr. Med. 13, 9–23 (1956).
5. Nagelschmidt, G., Rivers, D., King, E. J., Trevella, W.: Dust and collagen content of lungs of coal-workers with progressive massive fibrosis. Brit. J. industr. Med. 20, 181–191 (1963).