求翻译：参考文献：数字逻辑（第四版，欧阳星明，于俊清主编），计算计算法基础（第三版，余祥宣，崔国华，邹海明），数字系统的VHDL（汪国强主编）。是什么意思？

References: Digital Logic (fourth edition, Ouyang Star, Jun Qing editor), calculation of the calculation basis (third edition, Yuxiang Xuan, Cui Guohua Zou Haiming), digital systems, VHDL (Wang Guoqiang editor).

References: digital logic (version 4, O-stars, the editor-in-law computing infrastructure (version 3, Yu-hsiang-sun Choi Guohua, Zou, sea) and the digital system (Wang Guoqiang VHDL editor).

Reference: Digital logic (fourth edition, the Ouyang star is bright, Chief Editor Yu Junqing), the computation computation method foundation (third edition, Yu Xiang proclaims, Cui national essence, Zou Haiming), number system VHDL (Chief Editor Wang Guoqiang).

References: digital logic (Fourth Edition, Xing ming, Yu Junqing, editor), the basis for calculating the calculation method (Third Edition, Yu Xiangxuan, Cui Guohua, Zou Haiming), VHDL for digital systems (Editor, Wang Guoqiang).