A successful essay should possess the following:
3) Bridging to at least 2 sources in other disciplines. The sources must be substantial and/or scholarly; substantial, scholarly sources are journal articles from peer-reviewed journals and publications written by scholars/academics/experts and published by academic presses, not encyclopedia entries or anything found through Google.
Oxford Reference is great to cite something quick but does not count as doing real research. The art of doing and using research is about how you put things together. Which secondary sources are you going to use in order to put your original thing together? Whose perspectives will be invited to your party? Be deliberate with what you choose, and thoughtful about the seating arrangements!
NOTE: I want this paper to be about how Thoreau adds to climate change and nature and religion which are the two other interdisciplinary approach while also carefully analyzing his text. The sources used must neatly align with the textbook and how it relates to each other.