Subject: Does a fox/wolf hybrid really exist?

I'm very interesting by hybrids of all kind for the sake of curiosity but 
there is one which about I have very few information. About two years ago 
I've found on a animal book of the 50's the several canids with which a 
dog can mate, and it was mentioned that "with the fox,the dog can only 
mate with great difficulties". Some weeks ago I stumbled upon a science 
magazine of the 60's where it's written that "wolf/fox hybrids are very 
doubtful". Foxes seems to me darn far by DNA from a dog or a wolf to have 
offsprings but...I'm still puzzled. I didn't find more about it, can you 
help me?  

Re: Does a fox/wolf hybrid really exist?