Oka's lemma, convexity, and intermediate positivity conditions
  A new proof of Oka's lemma is given for smoothly bounded, pseudoconvex domains $D\subset\mathbb{C}^n$. The method of proof is then also applied to other convexity-like hypotheses on the boundary of $D$. 
A.-K. Herbig, J. D. McNeal
math.CV