On p-torsion of p-adic elliptic curves with additive reduction
  Let E be an elliptic curve with additive reduction over the p-adic numbers, and let G be the group of p-adic points on E that have good reduction. This paper gives necessary and sufficient conditions for G to contain non-trivial p-torsion. 
Ren\'e Pannekoek
math.AG math.NT