On the Zariski-Lipman conjecture for normal algebraic surfaces
  We consider the Zariski-Lipman Conjecture on free module of derivations for algebraic surfaces. Using the theory of non-complete algebraic surfaces, and some basic results about ruled surfaces, we will prove the conjecture for several classes of affine and projective surfaces. 
Indranil Biswas, R.V. Gurjar and Sagar U. Kolte
math.AG