?url_ver=Z39.88-2004&rft_id=http%3A%2F%2Fdx.doi.org%2F10.17654%2FMS101030643&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.au=Supandi%2C+Epha+Diana&rft.aulast=Supandi&rft.aufirst=Epha+Diana&rft.issue=3&rft.volume=101&rft.date=1+July+2017&rft.issn=ISSN%3A+0972-0871&rft.atitle=THE+OPTIMAL+PORTFOLIO+WEIGHTS+USING+THE+PROPORTIONAL+TYPE+ESTIMATORS&rft.title=Far+East+Journal+of+Mathematical+Sciences&rft.pages=643-657&rft.genre=article