Variations on the Theme of Journe's Lemma
  Journe's Lemma is a critical component of many questions related to the product ${BMO}$ theory of S.-Y. Chang and R. Fefferman. This article presents several different variants of the Lemma, some known, some implicit in the literature, and some new. 
Carlos Cabrelli, Michael Lacey, Ursula Molter, Jill C Pipher