RT Book, Section SR Electronic(1) A1 Higgs, Paul YR 2015 T1 How to perform upper GI endoscopy T2 BSAVA Congress Proceedings 2015 PB British Small Animal Veterinary Association DO 10.22233/9781910443521.16.1 UL https://www.bsavalibrary.com/content/chapter/10.22233/9781910443521.ch16sec1