Petzold, C. Touch for text. UI Frontiers. MSDN magazine.
Cita Chicago (17th ed.)Petzold, Charles. "Touch for Text. UI Frontiers." MSDN Magazine .
Cita MLA (9th ed.)Petzold, Charles. "Touch for Text. UI Frontiers." MSDN Magazine, .
Atenció: Aquestes cites poden no estar 100% correctes.