This document provides strategies for limiting database search results to higher levels of evidence, such as research studies, systematic reviews, and meta-analyses. It discusses publication type filters available in various databases, including limiting to "Research" in CINAHL, "Clinical trial, Meta-analysis, Randomized controlled trial" in PubMed, and "Empirical study, Systematic review, Meta analysis, Treatment outcome/randomized clinical trial" in PsycINFO. The strategies aim to filter literature search results to more rigorous studies.