Cardarelli, N.F. (1989). Role of the thymus in health and senescence: thymus and immunity (1 st Edition). Boca Raton, Florida. Pp: 23-25.
Dyce, K. M., Sack, W. O. & Wensing, C. J. G. (2010). Textbook of Veterinary Anatomy (4th Edition). Elsevier Health Sciences, Pp: 413-414.
Ettinger, S. J. & Feldman, E. S. (2005). Textbook of Veterinary Medicine (6th Edition). WB Saunders Company, Philadelphia. Pp: 1270.
Getty, R. (1975). Sisson & Grossmans. The Anatomy of the Domestic Animals (5th Edition). WB. Saunders Company. Pp: 1670.
Han, B. K., Babcock, D. S. & Oestreick, A. E. (1989). Normal Thymus in infancy: Sonographic Characteristics. Radiology. 170 (2): 471-474.
Kealy, J.K., McAllister, H. and Graham, J.P. (2010). Diagnostic Radiology and Ultrasonography of the Dog and Cat. 5ed. W.B. Saunders publisher, PP: 40-65.
Konde, L. J. & Spaulding, K. (1991). Sonographic evaluation of the cranial mediastinum in small animals. Veterinary Radiology. 32(4): 178-184.
Konig, H. E. & Liebich, H. G. (2007). Veterinary Anatomy of Domestic Mammals (3th Edition). Schattauer, Germany. Pp: 484-485.
Lavin, L. M. (2003). Radiology in Veterinary Technology (3rd Edition). WB. Saunders Company, Philadelphia, Pp: 244-248.
Nyland, T. G. & Mattoon, J. S. (2002). Small Animal Ultrasound (2nd Edition). WB Saunders Company, Philadelphia. Pp: 330-332.
Penninck, D. & dAnjou, M. A. (2008). Atlas of Small Animal Ultrasonography (2nd Edition). Wiley-Blackwell Publishing, Pp: 121.
Reichle, J. K. Wisner, E. R. (2000). Non-Cardiac Thoracic Ultrasound in 75 feline and canine patients. Veterinary Radiology and Ultrasound. 41(2): 154-162.
Safieddine, N., & Keshavjee, S. (2011). Anatomy of the thymus gland. Thoracic surgery clinics. 21(2), 191-195.
Thrall, D. E. (2013). Textbook of Veterinary Diagnostic Radiology (6th Edition). Saunders, Philadelphia. Pp: 386-388.
Young, B. James, S. Lowe, J. S. Stevens, A. & Heath, J. W. (2006). Wheater's Functional Histology: A Text and Colour Atlas (5th Edition). Churchill living stone Publisher, Pp: 162-165.