When I learned the first time some Bulgarian, I made some tables (grids) with pronomina and so on. I don't know excactly, which source I used. In one table I wrote:
"онизи, онази, (онуй), онези" in an other:
"оня, оная, онова, ония" and also:
"този, тази, (туй), тези" and finally:
"тоя, тая, това, тия"
But maybe I'm wrong. I couldn't even find my source up to now. But I know, it's not from internet.