@unpublished{repository45200,
            note = {Unpublished},
           title = {Surat Tugas, Undangan dan Sertifikat},
       publisher = {Universitas Muhammadiyah Prof. DR. HAMKA},
          author = {fetrimen, fetrimen},
             url = {http://repository.uhamka.ac.id/id/eprint/45200/}
}