Australia
Canada
Germany
UK
US
Rest of World

Australia

Paperback: 384 pages
Publisher: Vintage Australia (1 March 2013)
Language: English
ISBN-10: 174166862X
ISBN-13: 9781741668629
Also available as an e-book

Booktopia.com.au
Googleplay.com
Bookworld.com.au
Boomerangbooks.co.au
Seekbooks.com.au
TheNile.com.au

Canada

Hardcover: 384 pages
Publisher: Doubleday Canada (12 March 2013)
Language: English
ISBN-10: 0385666438
ISBN-13: 978-0385666435
Also available as an e-book

Amazon.ca
Googleplay.com
Indigo.ca
McnallyRobinson.com
Randomhouse.ca

Germany

Hardcover : 416 pages
Publisher: Hanser Berlin (25 February 2013)
Language: German
ISBN-10: 3446241523
ISBN-13: 978-3446241527
Also available as an e-book

Amazon.de
Buchhandel.de
Buecher.de
Googleplay.com

UK

Paperback: 384 pages
Publisher: Chatto & Windus (7 March 2013)
Language: English
ISBN-10: 0701183160
ISBN-13: 978-0701183165
Also available as an e-book

Amazon.co.uk
Googleplay.com
Blackwell.co.uk
Foyles.co.uk
Waterstones.co.uk
WHSmith.co.uk

US

Hardcover: 368 pages
Publisher: Pantheon (March 12, 2013)
Language: English
ISBN-10: 0307377393
ISBN-13: 978-0307377395
Also available as an e-book

Amazon.com
Barnesandnoble.com
Bookpassage.com
Googleplay.com
Indiebound.com
Randomhouse.com
Tatteredcover.com
Wallmart.com

Rest of World

More translations, and more retailers, are on the way. In the meantime, you can buy Sex and the Citadel from the following:

Amazon.com.br (Brazil)
Amazon.cn (China)
Amazon.es (Spain)
Amazon.fr (France)
Amazon.it (Italy)
Amazon.co.jp (Japan)
Bol.com (The Netherlands)
Buch.ch (Switzerland)
Exclusive Books (South Africa)
Fnac.com (France)
Fnac.pt (Portugal)
Googleplay.com
Infibeam.com (India)
Landmarkonthenet.com (India)
Kinokuniya.com.sg (Singapore)
Kinokuniya.com.my (Malaysia)
Kinokuniya.com.th (Thailand)
Saxo.com (Denmark)
Uread.com (India)
Whitcoulls.co.nz (New Zealand)