Solution to study three
The idea of this study is the repeated sacrifice of a rook to force stalemate and save an otherwise lost position. A further concept in the study is to regain both pawns hence reduce to a drawn R versus R+B ending. The idea game from some adjournment analysis of the game Donnelly-Berry, Manchester 1982.
The solution is
1. Rc3+ bxc3 stalemate.
..............Ka2 2. Ra3+ Kxa3 stalemate
...............................2...bxa3 stalemate.
...............b3 2. Rxb3+ Kxb3 stalemate
.....................................Ka4 3. Rc3 followed by Rxc2 reaches the drawn ending R+B v R.