Cite this article:

. . New Technology of Library and Information Service, 1996, 12(6): 50-51.

URL:

https://manu44.magtech.com.cn/Jwk_infotech_wk3/EN/10.11925/infotech.1003-3513.1996.06.12     OR     https://manu44.magtech.com.cn/Jwk_infotech_wk3/EN/Y1996/V12/I6/50