Don't worry, I'll let you know at class about the latest edition of Marketing Principles of Marketing. In fact, any edition of Kotler's famous textbook will do just fine. The principles don't change much, the main difference is in the examples which are updated regularly. 

• Santesmases, M. Marketing. Conceptos y estrategias. Madrid, Pirámide, 1999.
• Martin Armario, E. Marketing. Ariel, Barcelona, 1998.
• Lambin, J.J. Marketing estratégico, Madrid. McGraw Hill, 1995.
• Rodríguez Ardura, I. El Marketing y el éxito en la empresa (2ª ed.). Madrid: Pirámide, 1998.
• Kotler, P.; Armstrong, G.; Saunders, J.; Wong, V. Principles of marketing. The European Edition. Hertfordshire: Prentice Hall, 1999.