1. S. Kitao, H. Kameda, and M. Asaeda, MAKU (membrane) 15(4), 222 (1990).
2. S. Kitao and M. Asaeda, Key Engineering Materials 61 & 62, 267 (1991).
3. T. Okubo and H. Inoue, J. Chem. Eng. Jpn. 20(6), 590 (1987).
4. T. Okubo and H. Inoue, AIChE 34(6), 1031 (1988).
5. K. Nakagawa (Supervisor), Technical Data Collection; Gas Separation Technology and Industrial Use of Membranes, Mainly about Separation and Enrichment of Oxygen (Fuji Technosystem, Tokyo, 1983), p. 44.