1. Berger ML, Martin BC, Husereau D, Worley K, Allen JD, Yang W, et al. A questionnaire to assess the relevance and credibility of observational studies to inform health care decision making: an ISPOR-AMCP-NPC Good Practice Task Force report. Value Health J Int Soc Pharmacoeconomics Outcomes Res. 2014 Mar;17(2):143–56.

2. Hofmann B, Cleemput I, Droste S et al. Harmonization of ethics in health technology assessment: a revision of the socratic approach. Int J Tech Assess Health Care. 2014;30:3-9.

3.  Kristensen FB & Sigmund H (ed.)Health Technology Assessment Handbook Copenhagen: Danish Centre for Health Technology Assessment, National Board of Health, 2007