Siebeling, L., Wiebers, S., Beem, L., Puhan, M. A., & ter Riet, G. (2012). Validity and reproducibility of a physical activity questionnaire for older adults: Questionnaire versus accelerometer for assessing physical activity in older adults. Dove Medical Press.

Siebeling, Lara, Sarah Wiebers, Leo Beem, Milo A. Puhan, và Gerben ter Riet. Validity and Reproducibility of a Physical Activity Questionnaire for Older Adults: Questionnaire Versus Accelerometer for Assessing Physical Activity in Older Adults. Dove Medical Press, 2012.

Siebeling, Lara, et al. Validity and Reproducibility of a Physical Activity Questionnaire for Older Adults: Questionnaire Versus Accelerometer for Assessing Physical Activity in Older Adults. Dove Medical Press, 2012.