Invited commentary: comparison of food frequency questionnaires.
Willett
W C
WC
Department of Epidemiology and Nutrition, Harvard School of Public Health, Boston, MA 02115, USA.
D004034:Diet Surveys; D005502:Food / Q000706:statistics & numerical data*; D006801:Humans; D015203:Reproducibility of Results; D011795:Surveys and Questionnaires