SpringerLink (Online service), Porro, G. B., & Maconi, G. (2007). Ultrasound of the gastrointestinal tract. Springer-Verlag Berlin Heidelberg.
Cita Chicago (17th ed.)SpringerLink (Online service), Gabriele Bianchi Porro, i Giovanni Maconi. Ultrasound of the Gastrointestinal Tract. Berlin, Heidelberg: Springer-Verlag Berlin Heidelberg, 2007.
Cita MLA (8th ed.)SpringerLink (Online service), et al. Ultrasound of the Gastrointestinal Tract. Springer-Verlag Berlin Heidelberg, 2007.
Atenció: Aquestes cites poden no estar 100% correctes.