Timonen Markku, Laakso Mauri, Jokelainen Jari, Rajala Ulla, Meyer-Rochow V Benno, Keinänen-Kiukaanniemi Sirkka
Department of Public Health Science and General Practice, University of Oulu, Box 5000, FIN-90014, Finland.
BMJ. 2005 Jan 1;330(7481):17-8. doi: 10.1136/bmj.38313.513310.F71. Epub 2004 Dec 16.