%0 Book %A Symposium on Theoretical Aspects of Computer Science, )7th, 0991, Rouen, France( %T STACS 90 : 7th Annual Symposium on Theoretical Aspects of Computer Science, Rouen, France, February 22-24, 1990 : proceedings %U /book/72112196/STACS-90-7th-Annual-Symposium-on-Theoretical-Asp/