http://repository.uhamka.ac.id/id/eprint/15115/
Pengaruh Relationship Marketing terhadap Customer Retention di Kantor Pos DC Ciputat
Tamara, Anifi Okti
http://repository.uhamka.ac.id/id/eprint/15115/1/FKIP_PENDIDIKAN%20EKONOMI_1501085011_ANIFI%20OKTI%20TAMARA.pdf