F224.33
By means of the analysis and summarization of dummy arrow's application in the activity-on-arrow network, a judgment criterion for dummy arrow's existence, direction and quantity is given.
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