https://etd.repository.ugm.ac.id/penelitian/detail/239462004never1.0https://etd.repository.ugm.ac.id/penelitian/detail/239472004never1.0https://etd.repository.ugm.ac.id/penelitian/detail/239482004never1.0https://etd.repository.ugm.ac.id/penelitian/detail/239492004never1.0https://etd.repository.ugm.ac.id/penelitian/detail/239502004never1.0https://etd.repository.ugm.ac.id/penelitian/detail/252512004never1.0https://etd.repository.ugm.ac.id/penelitian/detail/252532004never1.0