Gaya APA
Kumar, V., Reinartz, W. (2018).
Customer relationship management : concept, strategy, and tools (Third Edition).
Jerman:
Springer-Verlag GmbH Germany.
Gaya MLA
Kumar, V.., Reinartz, Werner.
"Customer relationship management : concept, strategy, and tools".
Third Edition
Jerman:
Springer-Verlag GmbH Germany,
2018.
e-book.