536 Puzzles and Curious Problems

xii Introduction

For much of the information in my notes I am indebted to Victor Meally,
Dublin County, Ireland. Although he is mentioned often in the notes, there
are many places where I followed his excellent and generously given advice
without referring to him. I also wish to thank Harry Lindgren, Canberra,
Australia; Thomas H. Q'Beirne, Glasgow; and C. C. Verbeek, the Hague, for
other valuable suggestions.
Martin Gardner
HASTINGS-aN-HUDSON, N.Y.