1. 1) “Specifications for Timber Roadway Bridges”, Japanese Ministry of Construction, 1940.
2. 2) Fukuda, T.: Timber Engineering (in Japanese), edited by JSCE, Sobunsya, 1949.
3. 3) Gutkowski, R. M. and Williamson, T. G.: Timber Bridges-Developments and Trends in North America, 11th World Congress of the International Association of Bridge and Structural Engineers, 1980.
4. 4) Gutkowski, R. M. and Williamson, T. G.: Timber Bridges: State-of-the Art, Jour. of Struct. Eng., ASCE, Vol. 109, No. 9, pp. 2175-2191, 1983.
5. 5) Gutkowski, R. M. and Williamson, T. G.: Heavy Timber Structures and Bridges, Structural Wood Research-State of the Art and Research Needs, ASCE, pp. 111-130, 1983.