@unpublished{repository2232,
           title = {Sertifikat Pemateri},
       booktitle = {kolokium},
            note = {Unpublished},
            year = {2020},
           month = {June},
             url = {http://repository.uhamka.ac.id/id/eprint/2232/},
          author = {yulia, rahmadhar}
}