[espeed]

You mean this book by Leroux and Labelle? http://bergeron.math.uqam.ca/species/

(First 3 chapters: http://bergeron.math.uqam.ca/wp-content/uploads/2013/11/book...)

"Enumerative Combinatorics" is a different book by a different author (Richard P. Stanley, https://en.wikipedia.org/wiki/Richard_P._Stanley).