criminal law, one reference from outside source and another in the text book

In 3-4 paragraphs, name and define the three sources of law.  Rank the three sources of law, from highest to lowest. What do you think is the most important?

You are required to post an initial discussion post, answering the entire discussion question or questions,  no later than 11:59 p.m. Wednesday of the discussion week. Students must respond to the discussion posts of at least two of their classmates, no later than 11:59 p.m. Sunday of the discussion week. 

All initial posts should reference the textbook, Criminal Law, and, at least one outside source. All sources must be cited using APA guidelines. Posts received after 11:59 p.m. Sunday of the discussion week, will be deducted points.