- Breeders@ (4)
- www.algonet.se/~faidros/homesid1.htm
- Photo of Jonas, A portugese Mountain Dog from Dog of the day, January 9, 1999.dogoftheday.com/archive/1999/January/09.html
- Breed standard for the Estrela Mountain Dog.www.universalkennel.com/Standard%20Estrela%20Mountain%20Dog.htm