@unpublished{repository26146,
            note = {Unpublished},
           title = {sertifikat pengembangan instrumen},
       publisher = {Universitas Muhammadiyah Prof.DR.HAMKA},
             url = {http://repository.uhamka.ac.id/id/eprint/26146/},
          author = {Zulherman, Zulherman}
}