On 4-dimensional, conformally flat, almost $\epsilon$-K\"ahlerian   manifolds
  The local structure of 4-dimensional, conformally flat, almost $\epsilon$-K\"ahlerian (i.e., almost pseudo-K\"ahlerian and almost para-K\"ahlerian) manifolds is characterized with the help of left-regular and right-regular paraquaternionic functions. Examples of such structures are discussed. 
Karina Olszak and Zbigniew Olszak
math.DG