T. Gemma, S. Nakayama, Y. Takigawa, H. Ichikawa, T. Yamamoto, Y. Fukuda, T. Onuki, and T. Umeda, "testing at 1nm accuracy for sub-mm asphericity,"
in Optical Fabrication and Testing, A. Sawchuk, ed.,
Vol. 76 of OSA Trends in Optics and Photonics Series
(Optical Society of America, 2002), paper OWD4.