https://etd.repository.ugm.ac.id/penelitian/detail/180732000never1.0https://etd.repository.ugm.ac.id/penelitian/detail/182912000never1.0https://etd.repository.ugm.ac.id/penelitian/detail/182942000never1.0https://etd.repository.ugm.ac.id/penelitian/detail/183302000never1.0https://etd.repository.ugm.ac.id/penelitian/detail/183502000never1.0https://etd.repository.ugm.ac.id/penelitian/detail/186912000never1.0https://etd.repository.ugm.ac.id/penelitian/detail/186922000never1.0