Tamaki Ura, Takashi Obara; Sea trials of AUV "R-One robot" equipped with a closed cycle diesel engine system, Proceedings of MTS/IEEE OCEANS'97 Conference, pp. 987 - 993, September 1997.

Takashi Obara, Kitao Yamamoto, Tamaki Ura, Hisaaki Maeda, Hiroyuki Yamato; Basic design of an unmanned untethered submersible with a closed cycle diesel engine, Proceedings of the Eighth International Symposium on Unmanned Untethered Submersible Technology, vol. 8, pp. 411 - 419, September 1993.

Takashi Obara, Tamaki Ura; Development of depth independent closed cycle diesel engine for an autonomous underwater vehicle, Proceedings of the Seventh International Symposium on Unmanned Untethered Submersible Technology, vol. 7, pp. 1 - 9, September 1991.