参考文献:
Holloway, M. Katharine Liverton, Nigel J. Ludmerer, Steven W. McCauley, John A. Olsen, David B. Rudd, Michael T. Vacca, Joseph P. McIntyre, Charles J. Patent: US7/77 A, 7 Location in patent: Page/Page column 59 US 777 A
参考文献:
Chaudhari Nargund Journal of the University of Bombay, Science: Physical Sciences, Mathematics, Biological Sciences and Medicine, 948 , vol. 7/3A, p. 5