El sistema de coordenades anglès <a href="http://lin-ear-th-inking.blogspot.com/2011/09/everything-you-wanted-to-know-about-uk.html">http://lin-ear-th-inking.blogspot.com/2011/09/everything-you-wanted-to-know-about-uk.html</a><br>
<br>Raf<br>