Tinjauan Kualitas Pelayanan Customer Service pada GRAPARI Telkomsel Cabang Lubuk Alung Syukra, Alfi Fakultas Ekonomi Tasman, Abel Maulana, Arif Andriani, Chichi thesis https://repository.unp.ac.id/id/eprint/42599/ https://repository.unp.ac.id/id/eprint/42599/1/final_B1_07_ALFI_SYUKRA_16134005_4061_2020%20%281%29.pdf open access 2020-03 KUALITAS PELAYANAN