APA

Brualdi R., .introductory Combingatorics. new york:pearson,2009: .

Chicago

Brualdi Richard, .introductory Combingatorics. new york:pearson,2009: .

Harvard

Brualdi R., .introductory Combingatorics. new york:pearson,2009: .

MLA

Brualdi Richard, .new york:pearson,2009: . .