Immanuel Zai, Cerina, Tohmeng, Laurentcia Longli, Sweet Chen, and Vina Kristini, “Pengembangan Customer Relationship Pada Penggunaan Jasa Air Freighter DHL Global Forwarding Semasa Pandemi COVID-19”, JIM, vol. 1, no. 4, pp. 870–881, Mar. 2022.