1. Nakahata C, Aruga K, Takei Y, Yamaguchi R, Ito K, Murakami A, Saito M, Tasaka T, Kanetsuki K. 2011. Improvement on operational efficiencies and costs of extracting thinned woods using a processor and a forwarder in Nasunogahara area (II) based on comparative analyses of current operations and mechanized operations. Bulletin of Utsunomiya University Forest, 47: 27–34 (in Japanese with English summary).
2. Yamasaki T, Tokuhisa K, Miyata H. 2011. Technical support for establishing the low cost logging system. Bulletin of Kochi Prefectural Forestry Technology Research Center, 36: 40–67 (in Japanese with English summary).
3. Goto J, Takeda A. 2009. On the operation system to make the efficient use of the movable type forwarder. Journal of the Forestry Mechanization Society, 668: 9–15 (in Japanese).
4. Takahashi T. 2008. Introducing a removal type forwarder machine: An efficient log production system with the use of a removable type forwarder machine. Journal of the Forestry Mechanization Society, 657: 23–27 (in Japanese).