Cita APA (7th ed.)

PARKER, J. (2001). Emma's problem.-- ed.1. McGraw-Hill Interamericana.

Cita Chicago (17th ed.)

PARKER, John. Emma's Problem.-- Ed.1. Mexico: McGraw-Hill Interamericana, 2001.

Cita MLA (9th ed.)

PARKER, John. Emma's Problem.-- Ed.1. McGraw-Hill Interamericana, 2001.