Ask your professor and/or advisor their requirements for citation format. Bluebook Style is usually used for scholarly legal articles.
As a START, you can highlight part of the document in Westlaw and pick Copy with Reference (Standard). BUT be sure to SET PREFERENCES (click on the person icon in the upper right and select Preferences. Then select Copy Citation & Copy with Reference) to Citation Style - Law Reviews. Westlaw is not 100% accurate, so you must check the results with your Bluebook. Lexis also has a copy with citation feature but does not work as well for Law Review style Bluebook.
The Bluebook, Twenty First Edition by 
Contact the library staff with your Bluebook questions. Or, consult one of these resources: