@unpublished{repository33110,
            note = {Unpublished},
           title = {Sertifikat Visiting lecture},
       publisher = {Universitas Muhammadiyah Prof. Dr. Hamka},
             url = {http://repository.uhamka.ac.id/id/eprint/33110/},
          author = {Chandra Dewi S., CDS}
}