@manual{repository2231,
            type = {Documentation},
           title = {surat undangan , sertifikat dan materi sma 75 april 2019 no 33},
       publisher = {MM UHAMKA},
          author = {Bambang, Dwi Hartono},
             url = {http://repository.uhamka.ac.id/id/eprint/2231/}
}