张玉强 彭在萍. 双代号网络图绘制中的虚箭线判定—存在、指向及数目[J]. 土木与环境工程学报（中英文）, 2003,25(1):90-93.

Judgment of Dummy Arrow in the Activity-on Arrow Network- Existence, Direction and Quantity[J]. Journal of Civil and Environmental Engineering, 2003, 25(1): 90-93.

张玉强 彭在萍. 双代号网络图绘制中的虚箭线判定—存在、指向及数目[J]. 土木与环境工程学报（中英文）, 2003,25(1):90-93. DOI： 10.11835/j.issn.1674-4764.2003.01.019.

Judgment of Dummy Arrow in the Activity-on Arrow Network- Existence, Direction and Quantity[J]. Journal of Civil and Environmental Engineering, 2003, 25(1): 90-93. DOI： 10.11835/j.issn.1674-4764.2003.01.019.