International Energy Agency & IEA International Conference on Clean and Efficient Use of Coal and Lignite. (1994). The clean and efficient use of coal and lignite: Its role in energy, environment, and life : Hong Kong, 30th November-3rd December 1993 : conference proceedings. Energy Agency.
Παραπομπή σε μορφή Chicago (17η εκδ.)International Energy Agency και IEA International Conference on Clean and Efficient Use of Coal and Lignite. The Clean and Efficient Use of Coal and Lignite: Its Role in Energy, Environment, and Life : Hong Kong, 30th November-3rd December 1993 : Conference Proceedings. Paris: Energy Agency, 1994.
Παραπομπή σε μορφή MLA (9th εκδ.)International Energy Agency και IEA International Conference on Clean and Efficient Use of Coal and Lignite. The Clean and Efficient Use of Coal and Lignite: Its Role in Energy, Environment, and Life : Hong Kong, 30th November-3rd December 1993 : Conference Proceedings. Energy Agency, 1994.