There seems to be no end to the search variations Google is giving us. If you’re looking for “scholarly literature” only, you can save yourself having to weed through all the extraneous results by going to Google Scholar. Here is Google’s explanation:
What is Google Scholar?
Google Scholar provides a simple way to broadly search for scholarly literature. From one place, you can search across many disciplines and sources: peer-reviewed papers, theses, books, abstracts and articles, from academic publishers, professional societies, preprint repositories, universities and other scholarly organizations. Google Scholar helps you identify the most relevant research across the world of scholarly research.