Ann Intern Med, Vol. 147, No. 4. (21 August 2007), pp. 224-233.
The Medical journal of Australia, Vol. 185, No. 5. (4 September 2006), pp. 263-267.
Trials, Vol. 9 (18 April 2008), 20.
JAMA, Vol. 285, No. 15. (18 April 2001), pp. 1992-1995.
BMC Medical Research Methodology, Vol. 6 (18 July 2006), 33.
Ann Oncol, Vol. 9, No. 5. (1998), pp. 483-7.
Jama, Vol. 285, No. 15. (2001), pp. 1992-5.
Arch Pediatr Adolesc Med, Vol. 152, No. 9. (1998), pp. 915-20.
Bmj, Vol. 317, No. 7165. (1998)
Jama, Vol. 279, No. 18. (1998), pp. 1489-91.
Arch Pediatr Adolesc Med, Vol. 152, No. 7. (1998), pp. 700-4.
Arch Pediatr Adolesc Med, Vol. 152, No. 8. (1998), pp. 812-7.
Jama, Vol. 280, No. 3. (1998), pp. 278-80.
Aten Primaria, Vol. 21, No. 6. (1998), pp. 351-2.