https://etd.repository.ugm.ac.id/penelitian/detail/682112014never1.0https://etd.repository.ugm.ac.id/penelitian/detail/699242014never1.0https://etd.repository.ugm.ac.id/penelitian/detail/704252014never1.0https://etd.repository.ugm.ac.id/penelitian/detail/704532014never1.0https://etd.repository.ugm.ac.id/penelitian/detail/718172014never1.0https://etd.repository.ugm.ac.id/penelitian/detail/743522014never1.0https://etd.repository.ugm.ac.id/penelitian/detail/753142014never1.0https://etd.repository.ugm.ac.id/penelitian/detail/770722014never1.0