Whenever you want to leave out material from within a quotation, you need to use an ellipsis, which is a series of three periods, each of which should be preceded and followed by a space.
Barzun, Jacques, and Henry F. We need to have laws prohibiting the use of cell phones while driving. You'll still have a thesis and will need to back up your opinion with evidence from the work, but this type of paper spotlights your individual reaction as a reader or viewer.
For guidance on formatting citations, please see the UNC Libraries citation tutorial. This would downplay your own voice and leaves little room for your own ideas. If your attribution precedes the quote, you will need to use a comma after the verb.
For example, if you take material from the end of a sentence, keep the period in as usual.
You should consult a style manual for complicated situations, but the following two rules apply to most cases: Keep periods and commas within quotation marks. Develop your ideas by adding examples, quotations, and details to your paragraphs.
There is no need to put a period at the end. Even if you have provided some context for the quote, a quote standing alone can disrupt your flow. Boller, Jr. Colomb, and Joseph M.