... loai hai loai trung Id trung thdnh ddi han vd trung thdnh ngan han Khach hang trung ddi han khdng de'thay doi IlllM hQC '^ tltifdng mai 115 QUAN TR| KINH DOANH nha cung cap, khach hang trung thdnh ... dyng moi 2.3 Ldng trung cda khach hang quan h§ lau dai vdi khach hang {Patterson vd Ldng trung cua khach hang dd dupc ddng nghiep, 1997) vd vgy ma cac to chQc nghien cUu tU hdn nam mUdI ndm qua, ... mdi quan he giQa cac khai mem nghien Berry de xuat vdo nam 1985 vdi 10 yeu to va sau cUu nay, giup cho cac nhd quan tri nganh ngan dd vao nam 1988, Zeithaml, Parasuraman, vi hang tang va luu giQ...