[MathOuvrage]
Handbook of proof theory
/ Ed. Buss, Samuel R..
-Amsterdam : North-Holland, 1998. - vii, 811 p. ; 23 cm
ISBN 9780444898401
[MathOuvrage]
Complexity and approximation
/ Ausiello, Giorgio ; Crescenzi, P. ; Gambosi, G. ; Kann, V. ; et al..
-Berlin, Heidelberg, New York NY : Springer, 1999. - xix, 524 p. ; 25 cm