Which of the following statement regarding mixed tumors of the salivary glands, is true?

Pleomorphic adenoma or mixed tumor of salivary gland is the most common salivary gland tumor accounting for 70% of all salivary gland tumors. 80% of these are located in the parotid gland and presents as a firm, slow-growing mass. Ref: CURRENT Diagnosis and Treatment in Otolaryngology Head and Neck Surgery, 3rd Edition, Chapter 18; Essentials of Anatomic Pathology By Liang Cheng, 2nd Edition, Page 764; Harrison's Principles of Internal Medicine, 18th Edition, Chapter 32.