[1] Tonomora Akira et al. J. Electron Microsc,1979:28(1): 1
[2] Mollenstedt G et al Zeitschrift fur Physik, 1956;145 (3): 377
[5] Fu Shufen et al. Abstracts of International Symposium on Electron Optics, Sept 9~13, ]986, Beijing, China, p. 33
[6] Fu Shufen et al. Optik, 1987, to be published soon