1. Balon, E.K. 1988. Tao of life: universality of dichotomy in biology. 1. The mystic awareness. Rivista di Biologia/Biology Forum 81: 185–230 (in English and Italian).
2. Elton, C. 1940. Scholasticism in ecology. J. Anim. Ecol. 9: 151–152.
3. Huxley, T.H. 1863. On our knowledge of the causes of the phenomena of organic nature: being six lectures to working men, delivered at the Museum of Practical Geology. Robert Hardwicke, London. 156 pp.
4. Imanishi, K. 1949. The logic of organic society. Mainichi Newspaper Co., Tokyo. 256 pp. (in Japanese).
5. Ishikawa, C. 1934. Ishikawa's general zoology and botany with illustrations. Gakugei-shoin, Tokyo, 3 + 9 + 280 + 13 pp., 72 plates (in Japanese).