Hey Blue,

Black Russian seeds will be very hard to come by. I am not sure if they are even commercially available at this point.

Subcool and TGA Seeds did a lot of work with her though.

Here are a few of their strains that have utilized the BR.

Pinky (Sputnik) - Apollo 13 x Black Russian

Neon Super Skunk - Super Skunk x Black Russian

Double Purple Doja - Black Russian x Sputnik

Keep the Peace