https://etd.repository.ugm.ac.id/penelitian/detail/316062006never1.0https://etd.repository.ugm.ac.id/penelitian/detail/316092006never1.0https://etd.repository.ugm.ac.id/penelitian/detail/316112006never1.0https://etd.repository.ugm.ac.id/penelitian/detail/324732006never1.0https://etd.repository.ugm.ac.id/penelitian/detail/324742006never1.0https://etd.repository.ugm.ac.id/penelitian/detail/324752006never1.0https://etd.repository.ugm.ac.id/penelitian/detail/324782006never1.0https://etd.repository.ugm.ac.id/penelitian/detail/341722006never1.0