[MathOuvrage]
Boundary value problems
/ Powers, David L..
-Boston MA, London, San Diego CA : Academic press, 1999. - xi, 528 p. ; 24 cm
[MathOuvrage]
Zero-symmetric graphs
/ Coxeter, Harold S. M. ; Frucht, Roberto ; Powers, David L..
-London, New York NY, Toronto : Academic press, 1981. - ix, 170 p. ; 24 cm