Search strategies for locating various types of articles:
PubMed and Embase have published searches to locate retracted articles.
For PubMed, open the tab for "Topic Specific Queries" and scroll down to the retracted article search.
Our suggested search to locate errata, corrigenda or "expressions of concern" in PubMed is:
"Published Erratum"[Publication Type] OR errata OR erratum OR corrigenda OR corrigendum OR "expression of concern"