https://etd.repository.ugm.ac.id/penelitian/detail/684522014never1.0https://etd.repository.ugm.ac.id/penelitian/detail/729962014never1.0https://etd.repository.ugm.ac.id/penelitian/detail/737532014never1.0https://etd.repository.ugm.ac.id/penelitian/detail/740422014never1.0https://etd.repository.ugm.ac.id/penelitian/detail/746012014never1.0https://etd.repository.ugm.ac.id/penelitian/detail/754372014never1.0https://etd.repository.ugm.ac.id/penelitian/detail/761412014never1.0https://etd.repository.ugm.ac.id/penelitian/detail/769622014never1.0