What are the top three databases that are used for research papers?

What are the top three databases that are used for research papers?For this Discussion, view the webinar in this week’s resources by a Walden University librarian on strategies to conduct a successful literature search. The webinar provides information on available databases, the use of search engines, and the selection of search terms. Then, you will conduct a literature search on research conducted in the last 5 years on the patient safety problem you identified in Week 1. Resources Be sure to review the Learning Resources before completing this activity. Click the weekly resources link to access the resources. WEEKLY RESOURCES By Day 3 Post the following: For the literature search, describe the following in your post: The databases, search engines, and search terms you used in your literature search. The number of research articles you found on your patient safety problem that were published in the last five years. The challenges you encountered locating research articles and how you overcame them. Who you would go to for help in your work setting if you needed help with a literature search. Note: Post a 3-paragraph (at least 350 words) response. Be sure to use evidence, in-text citations, and essay-level writing skills, including the use of transitional material and organizational frames. Use the writing resources and the Discussion Rubric to develop your post. By Day 7 Read two or more of your colleagues’ postings from the Discussion question. Respond to two or more of your colleagues with a comment that asks for clarification, provides support for, or contributes additional information. Post a Discussion entry on 3 different days of the week. See the Discussion Rubrics for more information.