Cita APA

Norman Lewis & Wilfred Funk. 30 Days to a more powerful vocabulary. New York.

Chicago Edition Citation

Norman Lewis i Wilfred Funk. 30 Days to a More Powerful Vocabulary. New York.

Cita MLA

Norman Lewis i Wilfred Funk. 30 Days to a More Powerful Vocabulary. New York.

Atenció: Aquestes cites poden no estar 100% correctes.