joining tables
An embedded and charset-unspecified text was scrubbed... Name: no disponible URL: <https://stat.ethz.ch/pipermail/r-help/attachments/20111004/b3b1cc8d/attachment.pl>
An embedded and charset-unspecified text was scrubbed... Name: no disponible URL: <https://stat.ethz.ch/pipermail/r-help/attachments/20111004/b3b1cc8d/attachment.pl>