* {{cite book |first=Stephen |last=Wiggins |title=Global bifurcations and Chaos: Analytical Methods |year=1988 |publisher=Springer |location=New York |isbn=978-0-387-96775-2 |url=https://books.google.com/books?id=s1zdBwAAQBAJ }} | * {{cite book |first=Stephen |last=Wiggins |title=Global bifurcations and Chaos: Analytical Methods |year=1988 |publisher=Springer |location=New York |isbn=978-0-387-96775-2 |url=https://books.google.com/books?id=s1zdBwAAQBAJ }} |