SpringerLink (Online service), Porro, G. B., & Maconi, G. (2007). Ultrasound of the gastrointestinal tract. Springer-Verlag Berlin Heidelberg.
Čikaški stil citiranja (17. izdanje)SpringerLink (Online service), Gabriele Bianchi Porro, i Giovanni Maconi. Ultrasound of the Gastrointestinal Tract. Berlin, Heidelberg: Springer-Verlag Berlin Heidelberg, 2007.
MLA način citiranja (8. izdanje)SpringerLink (Online service), et al. Ultrasound of the Gastrointestinal Tract. Springer-Verlag Berlin Heidelberg, 2007.
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