This magazine looks like what you want for game bird raising info
I'm seeing a variety of ways of sexing this variant and one is some feel the white bib is on the males, or the black head markings is on the males. Another said the easiest way is to band the ones you see trying to mount other birds as males. Most of the males have a black mask and a white patch on their chest but not all of them.
And this site has a book on sexing all birds
Hope this helps you!