This is an example of the progression your research might take. Start with Wikipedia, follow that with the Internet Encyclopedia of Philosophy, and move then to the Stanford Encyclopedia of Philosophy. In the future, you should follow a similar path along with any required readings (in this case, The Tragedy of the Commons). You may not directly quote or use Wikipedia as a source for your paper, it is there for you to use to get up to speed before digging into your research.
Recommended reading: Introduction to Ethical Egoism (Wikipedia)
REQUIRED READING: INTRODUCTION TO ETHICAL EGOISM (IEP)
REQUIRED READING: INTRODUCTION TO ETHICAL EGOISM (SEP)
REQUIRED READING: THE TRAGEDY OF THE COMMONS
In 500 words or more (no less), explain the difference between psychological egoism and enlightened ethical egoism. You may use examples, but you will still need to include a full scholarly definition of each, with commentary. You may use any scholarly source other than a dictionary, to include online video lectures. You may use Wikipedia as a starting point, but be aware that Wikipedia is not a scholarly source and therefore can never be quoted in your paper or counted as 1 of your 5 bibliographic citations.
You will need to include inline citations in your essay (last name, date, pg#) and must still cite any sources beyond the five required that you use to write your paper in the references section of your essay. If you include an inline citation, there must be a corresponding entry in the reference list or bibliography. You can find tools and examples of APA citation formats at the Purdue University Online Writing Lab.
You are required to submit a separate annotated bibliography. Using the resource center and the scholarly research tools I listed in the course introduction, for your research. With that information, create an annotated bibliography with 5 sources related to the ethical theory of the week.