Mølgaard Christian, Sandström Brittmarie, and Fleisher Michaelsen Kim. “Evaluation of a Food Frequency Questionnaire for Assessing of Calcium, Protein and Phosphorus Intakes in Children and Adolescents”. Food & Nutrition Research (December 1, 1998): 2-5. Accessed April 19, 2024. https://foodandnutritionresearch.net/index.php/fnr/article/view/87.