@techreport{oai:tsukuba.repo.nii.ac.jp:00022710,
 author = {Sumita, Ushio and Yonezawa, Kouichi},
 month = {},
 note = {Includes bibliographical references},
 title = {Stochastic analysis of number of corporations in a market derived from strategic policies of individual corporations for market entry and retreat},
 year = {2003}
}