@unpublished{repository49228,
           title = {Surat Tugas,Undangan dan Sertifikat Pengabdian},
       publisher = {Universitas Muhammadiyah Prof. DR. HAMKA},
            note = {Unpublished},
             url = {http://repository.uhamka.ac.id/id/eprint/49228/},
          author = {fetrimen, fetrimen}
}