Robles, G. (2013). Sketchbook Pro digital painting essentials. Packt Publishing.
Cita Chicago (17th ed.)Robles, Gil. Sketchbook Pro Digital Painting Essentials. Birmingham: Packt Publishing, 2013.
Cita MLA (9th ed.)Robles, Gil. Sketchbook Pro Digital Painting Essentials. Packt Publishing, 2013.
Atenció: Aquestes cites poden no estar 100% correctes.