References
  ~~~~~~~~~~

  Heath, R.W., Screenability, pointwise para-
  compactness, and metrization of Moore spaces. 
  Canadian J. Mathem. 16 (1964), pp. 763-770.

  Johnstone, P.T., Linton, F.E.J. and Paré, R., 
  Injectives in Topoi, II: Connections with the
  Axiom of Choice. In: Categorical Topology,
  Proceedings, Berlin, 1978; Springer LNM 719, 
  1979, pp. 207-216.