Retrieving studies from databases for a systematic review

I am currently devising a systematic review and seeking the assistance of a librarian to conduct searches across several databases, including but not limited to PubMed, Cochrane Database Library, Embase Database Library, Scopus, and ProQuest Dissertations and Theses Global. The librarian will employ a combination of keywords and controlled vocabulary, such as MeSH and EMTREE, to accurately identify studies related to the concepts under investigation and retrieve them.