https://etd.repository.ugm.ac.id/penelitian/detail/1880602020never1.0https://etd.repository.ugm.ac.id/penelitian/detail/1880642020never1.0https://etd.repository.ugm.ac.id/penelitian/detail/1881282020never1.0https://etd.repository.ugm.ac.id/penelitian/detail/1881412020never1.0https://etd.repository.ugm.ac.id/penelitian/detail/1939552020never1.0https://etd.repository.ugm.ac.id/penelitian/detail/1939582020never1.0https://etd.repository.ugm.ac.id/penelitian/detail/1993012020never1.0