https://etd.repository.ugm.ac.id/penelitian/detail/507042011never1.0https://etd.repository.ugm.ac.id/penelitian/detail/507382011never1.0https://etd.repository.ugm.ac.id/penelitian/detail/507392011never1.0https://etd.repository.ugm.ac.id/penelitian/detail/507472011never1.0https://etd.repository.ugm.ac.id/penelitian/detail/507712011never1.0https://etd.repository.ugm.ac.id/penelitian/detail/508062011never1.0https://etd.repository.ugm.ac.id/penelitian/detail/508382011never1.0https://etd.repository.ugm.ac.id/penelitian/detail/526642011never1.0https://etd.repository.ugm.ac.id/penelitian/detail/528162011never1.0