Gaya APA

Tunggal, A, W. (2014). Dasar dasar Customer Relationship Management (CRM) (Cet.1 ). : Harvarindo.

Gaya MLA

Tunggal, Amin, Widjaja. "Dasar dasar Customer Relationship Management (CRM)". Cet.1 : Harvarindo, 2014. Text.