@article{Przesławski:1992,
  author  = "K. Przesławski and L. Rybiński",
  title   = "Concepts of Lower Semicontinuity and Continuous Selections for Convex Valued Multifunctions",
  journal = "Journal of Approximation Theory",
  volume  = "Vol. 68",
  number  = "iss. 3",
  pages   = "262--282",
  year    = "1992",
}