Cuba: [email protected]

Ecuador: [email protected]

El Salvador: [email protected]

México: [email protected]  &  [email protected]

Perú: [email protected]

RFA: [email protected]  &  [email protected]

Venezuela: [email protected]

Páginas de Internet:

http://www.puk.de/download

http://www.dcs.gla.ac.uk/wpc/