John Grogan. (2011). Marley: Messy Dog (I Can Read Level 2) (Reprint.). HarperCollins.
Cita Chicago (17th ed.)John Grogan. Marley: Messy Dog (I Can Read Level 2). Reprint. HarperCollins, 2011.
Cita MLA (9th ed.)John Grogan. Marley: Messy Dog (I Can Read Level 2). Reprint. HarperCollins, 2011.
Atenció: Aquestes cites poden no estar 100% correctes.