Citations

Lots of other information on skyscrapers   Websites http://www.infoplease.com: (World's tallest buildings) http://www.building.com.hk http://www.centralplaza.com.hk http://www.cheungkongcenter.com http://www.emporis.com: (World's tallest skyscrapers) http://www.howstuffworks.com: (Which is the tallest building in the world?) (How skyscrapers work) (How Iron and Steel work) http://www.cnn.com: (Freedom Tower in plan) (Freedom Tower cornerstone) (Skyscraper Tragedies) (Milan's tallest building collision) http://www.news.bbc.co.uk (Skyscraper incidents) http://www.glasssteelandstone.com: (Freedom Tower) http://www.americaspirit.tripod.com/usaspecial2.html http://www.glassonweb.com http://www.skyscrapers.org 　   Magazines Time Magazine: Issue August 16, 2004 Books New Technology: Structures and Buildings, by Nigel Hawkes. Gloucester Press, 1995 Physical Science: Structures, by Gareth Stevens. Discovery Channel School Science, 2003 Constructions for Towering Intellects, by Chris Oxlade. Hodder Children's Books, 1997 How They Were Built, by David J. Brown. Kingfisher Books, 1991 Big Book of How Things Work, The, by Peter Lafferty. The Octopus Publishing Group Ltd, 1990 Seven Wonders of the Modern World, The, by Reg Cox & Neil Morris. Silver Burdett Press X-Ray Picture Book of Big Buildings of the Ancient World, The, by Joanne Jessop. The Salariya Book Co Ltd, 1993 Skyscrapers and Towers, by Chris Oxlade. Belitha Press Limited, 1996 Skyscrapers, by Andrew Dunn. Wayland Publishers, 1992 Skycrapers, by Chris Oxlade. Heinemann Library 2001