APA

International Gas Union I., World Gas Conference (23rd. : 2006 jun 5-9 : Amsterdam T. N., .Sustainable urban system design. : .

Chicago

International Gas Union IGU, World Gas Conference (23rd. : 2006 jun 5-9 : Amsterdam The Netherlands), .Sustainable urban system design. : .

Harvard

International Gas Union I., World Gas Conference (23rd. : 2006 jun 5-9 : Amsterdam T. N., .Sustainable urban system design. : .

MLA

International Gas Union IGU, World Gas Conference (23rd. : 2006 jun 5-9 : Amsterdam The Netherlands), .: . .