Battersby, Albert
Sales forecasting
Penguin Books, 1968
 Buku Teks SO
Cortada, James W.
TQM for sales and marketing management
McGraw-Hill, 1993
 Buku Teks SO
Foster, Dennis L.
Sales and marketing for the travel professional
Glencoe, 1993
 Buku Teks SO
Foster, Dennis L.
Sales and marketing for the travel profesional
RajaGrafindo Persada, 2000
 Buku Teks SO
Foster, Dennis L.
Sales and marketing for the travel professional
Glencoe, 1993
 Buku Teks SO