Journal searching, even when searching local preprint and journal databases may be insufficient to 'surface' all the relevant papers. Adding a 'Grey Literature' search may highlight key local policies and less formal publications that may be highly valid in their own right, and also reference key research that may have been missed in the literature search.
About Internal and External Validity
High-quality research produced in large UK/US multicentre studies might be 'Internally Valid', which is an excellent piece of research. They may however show very poor 'External Validity in a worldwide context, where it is difficult to apply to a demographically varied LMIC setting. A good 'Grey Literature Search' can add additional External Validity to research.
Further information on Grey Literature searching can be found on the Grey Literature LibGuide and Decolonising Literature Searching LibGuide
The Library also presented a talk on the 'Decolonising of Grey Literature' for part of the 'Systematic Review Conversations' from Lancaster University. Available on YouTube.
The library has recently added Overton.io to our databases. Overton is the world’s largest searchable index of policy documents, guidelines, think tank publications and working papers and collects data from 182 countries and over a thousand sources worldwide with more being added all the time. Access via the Databases A-Z
Overton is very strong both in indexing policy documents from many different countries, and also contains a wide selection of limits for both countries and regional groupings. Using these limits can help you exclude countries and organisations that produce large amounts of guidance and policy (For example the WHO and NHS) and allow greater focus on local 'in-country' policy and guidance.
Trip Pro is a worldwide clinical search engine designed to allow users to quickly and easily find and use high-quality research evidence to support their practice and/or care with a strong focus on highlighting evidence-based resources. Trip searches PubMed, National and International guidelines, systematic reviews, clinical trials databases, blogs, leaflets, primary research and much more. Filters can be used to focus on LMIC policies and research. Access at the Database A-Z
Lens.org , originally called 'Patent Lens' is a worldwide patent search. The free version is also enhanced with patents, scholarly works, and biological sequence analysis, allowing users to see where these have been cited in research.
You can exclude certain regional groupings such as G7 and BRICS countries, or choose to only search those countries, along with the more common country-level filters.
Policy Commons is the largest and most comprehensive content-and-discovery platform and community resource for public policy. It delivers more than 2.5 million reports, working papers, policy briefs, data sources, and media drawn from a directory of more than 8,000 IGOs, NGOs, think tanks, and research centers.
Policy Commons indexes documents from 160 countries, including unique content from the Global South.