Watts (Wideman) K, McAvinchey G, Quiroz R. Language services in survey research. ATA Chronicle. 2002 Jul;31(7):36-7.
Campo R, Brullet E, Montserrat A, Calvet X, Rivero E, Brotons C. Topical pharyngeal anesthesia improves tolerance of upper gastrointestinal endoscopy: a randomized double-blind study. Endoscopy. 1995 Nov;27(9):659-64.