I did some searching around for you and the general consensus is that semi-hardwood cuttings taken in summer work the best and that the ripened seeds need to be stratified for 2 to 3 months above freezing. One source indicated that germination is spotty.

If I were you, I'd continue googling, as I only found a couple of links and that's not very much. I'm sure that there is more out there, just need to put the right spin on the search.