On Crawley Modules
  This continues recent work in a paper by Corner, Gobel and Goldsmith. A particular question was left open: Is it possible to carry over the results concerning the undecidability of torsion--free Crawley groups to modules over the ring of p-adic integers? We will confirm this and also strengthen one of the older results in by replacing the hypothesis of diamondsuit by CH. 
R\"udiger G\"obel and Saharon Shelah