Try these subjects headings when looking for sonography information:
The Gale EBOOKS medical encyclopedias provide basic information on your topic:
Type Ultrasound in the search box on the right side (above covers) and press Enter.
Check out these titles found in the Gale Virtual Reference Library:
You will find more reference books when searching the InfoTrac databases. Search your topic - then choose "Books" from "Your Results".
Taber's Medical Dictionary Online - Taber's Medical Dictionary Online provides more than 65,000 definitions, 32,000 audio pronunciations, 1,200 images, and 120 videos.