http://ca.wikipedia.org/wiki/Factors_de_producci%C3%B3

http://www.youtube.com/watch?v=EadQuaHZHtI

http://www.slideshare.net/jordimanero/1-recursos-naturals-pdf-2103135

http://www.youtube.com/user/Parlemdeconsum?blend=22&ob=5#p/u/26/WL9AIk45dmo

http://ca.wikipedia.org/wiki/Publicitat

http://www.acordestrategic.cat/noticies/67410021.html

http://www.ctescat.cat/scripts/larevista/article.asp?cat=8&art=378

http://www.oficinadetreball.cat/socweb/export/sites/default/socweb_ca/ciutadans/orientacioTrobarFeina/teletreball.html