 It would be an interesting project to compare the first two earlier books on graph theory, by Sainte-Lagu¨e [34] and K¨onig [31] respectively, with
the book by Berge [2].It is clear that Berge’s book is more leisurely and playful
than K¨onig’s, in particular.It is governed by the taste of Berge and might well be
subtitled ‘seduction into graph theory’ (to use the words of Rota from the preface
to the English translation of [13]).