1. Jüntgen, H. and K. H. van Heek, Coal gasification (in German) Thiemig Taschenbücher, 94, München 1981 (especially chapters 1, 2, 4 and 5 of the book)
2. Peters, W., H. Jüntgen and G. Kölling, Coals as an oil and gas replacement, Proceedings of 10th World Petroleium Congress, Vol. 3, London 1980
3. Jüntgen, H., J. Klein, K. Knoblauch, H. J. Schröter and J. Schulze, Conversion of Coal and Gases Produced from Coal into Fuels, Chemicals and other Products, Chemistry of Coal Utilization, 2nd Supplementary Volume. John Wiley and Sons, Inc., New York, 1981
4. Schilling, H.D., B. Bonn and U. Krauss, Coal Gasification: Existing Processes and New Developments, Graham & Trotman, London, 1981
5. Coal gasification technology, Status report prepared by a joint EEC-India study group, Comission of the European Communities, Brussels, 1980 - XII/1450/80-EN