Black Hole entropy by the brick wall method in four and five dimensions   with U(1) charges
  Using the brick wall method we compute the statistical entropy of a scalar field in a nontrivial background, in two different cases. These background are generated by four and five dimensional black holes with four and three U(1) charges respectively. The Bekenstein entropy formula is generally obeyed, but corrections are discussed in the latter case. 
Elcio Abdalla and L. Alejandro Correa-Borbonet