@unpublished{repository1720,
           title = {lampiran mengajar kimia fisika 2E},
            note = {Unpublished},
       publisher = {Universitas Muhammadiyah Prof DR HAMKA},
             url = {http://repository.uhamka.ac.id/id/eprint/1720/},
          author = {Elfiyani, Rahmah}
}