Author,Title,Journal,ISSN,Publisher,Date,Volume,Number,Page,URL,URL(DOI) Murai Yasumasa,A proposed WBS for Schedule development(Optimization for Project scheduling),Journal of the Society of Project Management,1345031X,The Society of Project Management,2004,6,3,16-20,https://cir.nii.ac.jp/crid/1390282681088425856,https://doi.org/10.14914/spmj.6.3_16