The correlation between the intake of lutein, lycopene and beta-carotene from vegetables and fruits, and blood plasma concentrations in a group of women aged 50-65 years in the UK.
Scott KJ, Thurnham DI, Hart DJ, Bingham SA, and Day K
The British journal of nutrition. Mar 1996
(DOI : 10.1079/bjn19960143)
Comparison of dietary assessment methods in nutritional epidemiology: weighed records v. 24 h recalls, food-frequency questionnaires and estimated-diet records.
Bingham SA, Gill C, Welch A, Day K, Cassidy A, Khaw KT, Sneyd MJ, Key TJ, Roe L, and Day NE
The British journal of nutrition. Oct 1994
(DOI : 10.1079/bjn19940064)