?url_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.au=Duong%2C+Ngoc+Son&rft.aulast=Duong&rft.aufirst=Ngoc+Son&rft.date=February+2021&rft.issn=1693-6930&rft.atitle=Smartphone+Indoor+Positioning+Based+on+Enhanced+BLE+Beacon+Multi-lateration&rft.title=TELKOMNIKA+Telecommunication%2C+Computing%2C+Electronics+and+Control&rft.pages=53-64&rft.genre=article