English summary

• Main Author: Gina Cariño
• Format: Article
• Language: English
• Published: Universidad Politécnica de Madrid 2009-07-01
• Series: Cuaderno de Notas
• Online Access: http://polired.upm.es/index.php/cuadernodenotas/article/view/864
• ISSN: 1138-1590

English summary