https://etd.repository.ugm.ac.id/penelitian/detail/130932000never1.0https://etd.repository.ugm.ac.id/penelitian/detail/130992000never1.0https://etd.repository.ugm.ac.id/penelitian/detail/131962000never1.0https://etd.repository.ugm.ac.id/penelitian/detail/131982000never1.0https://etd.repository.ugm.ac.id/penelitian/detail/132202000never1.0