CSG - Operations

Hi there! Does anybody have any good links to tutorials about CSG Operations? I need them for my Leveleditor! I know Dan Drawers site.. but it didn''t tell me to much. I already knew what subtraction (carving) and addition means.. What i really need is all the math behind it.. or maybe there''s some source code out there that could help? thx alot! cya, Phil Visit Rarebyte! and no!, there are NO kangaroos in Austria (I got this questions a few times over in the states