Preprint servers MedRxiv (biomedical), PsyArXiv (psychology and psychiatry) and BioRxiv (biological, including biochemistry, genetics, pharmacology).
EuropePMC is an open science platform that searches multiple sources including many preprint servers.
Filter for preprints using the left hand sidebar.
WHO's Clinical Trials Search Portal aggregates results from multiple trial registries.
ClinicalTrials.gov is a database of privately and publicly funded clinical studies conducted around the world maintained by the US National Library of Medicine.
Finding clinical trials, research registers and research results is a website listing multiple trial registries with information on search options for each.
Trip database is a search engine for biomedical and health material. Once searched look at the right hand sidebar to restrict results to guidelines, regulatory materials, blogs etc.
Guidelines International Network - large collection of international guidelines. Also has a website with useful resources for those developing guidelines.
International Health Technology Assessment database (IHTA) - access to information about health technology assessments from around the world.
Google Advanced Search. Use advanced search to restrict to particular domains eg .gov.au or file types eg .pdf.
Using Google for domain searching can be helpful if a sites internal searching capability is poor. Eg adding 'site:www.medrxiv.org' to a Google search will search within the MedRxiv site. More information on our Google for research guide.
OAIster searches institutional repositories and digital libraries.
Grey Matters includes an extensive list of national and international HTA web sites, drug and device regulatory agencies, clinical trial registries, health economics resources and drug formulary web sites. It is produced by the Canadian Agency for Drugs and Technologies in Health.
Analysis & Policy Observatory (APO) collects grey literature on many public policy areas, including health, from government, agencies, regulators, research institutes, non-for-profits and think tanks. Australian focused.
Use the ACCODS checklist to assess the quality of grey information on these criteria: Authority, Accuracy, Coverage, Objectivity, Date, Significance.