Every in-text citation must correspond with a full citation on the References page, and vice versa. You can't include a source in your references list if you don't also cite it in your paper.
Place at the end of a sentence, before the ending punctuation mark.
Narrative in-text citations incorporate citation elements into the text of the paper. The year can go in parentheses or also in the text.
If you are citing the same author in consecutive sentences, cite the source in the first sentence, and in the following sentences do not repeat the citation but instead make it clear in your writing that you are referring to the same source. In subsequent paragraphs, cite it again. More detail on long paraphrases here.
For short quotations of fewer than 40 words, add quotation marks around the words and incorporate the quote into your own text. Add the page number to the parenthetical citation.
You may also add a page number to make it easier for your reader to find the information, such as when citing within a book.
For longer quotations of more than 40 words, format the quote in its own paragraph, with the entire section indented 1/2". Do not use quotation marks around it, and include the standard citation information at the end.
For example, if you wished to quote the entire first paragraph of Alice's Adventures in Wonderland, that would be formatted as a block quote:
Alice was beginning to get very tired of sitting by her sister on the bank, and of having nothing to do: once or twice she had peeped into the book her sister was reading, but it had no pictures or conversations in it, 'and what is the use of a book,' thought Alice, 'without pictures or conversations?' (Carroll 9)
Notice that the block quote has no punctuation mark after the parenthetical citation.