?url_ver=Z39.88-2004&rft_id=10.1063%2F1.4995148&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.aulast=Purnomo&rft.au=Purnomo%2C+Yoppy+Wahyu&rft.aufirst=Yoppy+Wahyu&rft.date=2017&rft.issn=15517616&rft.title=Fractions+division+knowledge+of+elementary+school+student%3A+The+case+of+Lala&rft.isbn=9780735415485&rft.genre=proceeding