Encyclopedia of Energy McGraw-Hill Book Company Inc New York 2D Ed 1980 :136-139.
This article discusses four direct-liquefaction processes, two indirect-liquefaction processes, and developing third-generation processes. Also discussed are production constraints, prospects and issues, hydrogen for liquefaction processes, costs, and modifications of second-generation direct liquefaction processes.
Encyclopedia of Energy, McGraw-Hill Book Company, Inc., New York, 2D Ed., 1980, PP. 136-139.