Heartbeat & Breathe, a website that is dedicated to traditional folk singing – style and method. You can find a lot more links there, and also other interesting things about kulning. In English. Check it out!
UDDA TONER – a website where you can find Books, CD, Sheet-music etc in the field of Swedish Folk Music and Singing. In Swedish – so you will have to use Google translate. Check it out
Cow 
Herding forest 
Double kulning