Souvenir book International Puzzle. Party 20

Автор не известен.IPP20 Copyright, All rights reserved.
This document is made for distribution to the invitees of the 20 th International Puzzle Party and may contain material not open to the general public.
No part of this document may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, recording, or by any information storage or retrieval system, without written permission from the commitee of the 20 th International Puzzle Party (IPP20 Committee).
Individual puzzles and drawings are the copyright of the individual contributors.
Some designs may be the subject of patents or other forms of legal protection.