https://etd.repository.ugm.ac.id/penelitian/detail/1875332020never1.0https://etd.repository.ugm.ac.id/penelitian/detail/1895862020never1.0https://etd.repository.ugm.ac.id/penelitian/detail/1900002020never1.0https://etd.repository.ugm.ac.id/penelitian/detail/1917402020never1.0https://etd.repository.ugm.ac.id/penelitian/detail/1917762020never1.0https://etd.repository.ugm.ac.id/penelitian/detail/1934822020never1.0https://etd.repository.ugm.ac.id/penelitian/detail/1942382020never1.0