@unpublished{repository3200,
           title = {Surat Tugas Webinar Sado (PDF)},
            note = {Unpublished},
       publisher = {Universitas Muhammadiyah Prof. DR HAMKA},
             url = {http://repository.uhamka.ac.id/id/eprint/3200/},
          author = {Utari, Retno}
}