Where to find Mankai duckweed

I’m looking to buy wolffia globosa duckweed live plants but I cant seem to find them anywhere. I’m looking to grow them in my pond to collect, dry and use it as a winter feed mix for my ducks/chickens/goats and myself. I might use it as compost to. I’m hoping to become fully self sufficient and that is a big part of the feed mix I created to get them through the winter. I might even be able to use it for a substrate for my mealworm farm I’m planing to do. So where can I find them?