The samples that follow all quote, appropriately or inappropriately, from the following paragraph from page 3 of Middlemarch by George Eliot.

And how should Dorothea not marry?--a girl so handsome and with such prospects? Nothing could hinder it but her love of extremes, and her insistence on regulating life according to notions which might cause a wary man to hesitate before he made her an offer, or even might lead her at last to refuse all offers. A young lady of some birth and fortune, who knelt suddenly down on a brick floor by the side of a sick labourer and prayed fervidly as if she thought herself living in the time of the Apostles--who had strange whims of fasting like a Papist, and of sitting up at night to read old theological books! Such a wife might awaken you some fine morning with a new scheme for the application of her income which would interfere with political economy and the keeping of saddle-horses: a man would naturally think twice before he risked himself in such fellowship. Women were expected to have weak opinions; but the great safeguard of society and of domestic life was, that opinions were not acted upon. Sane people did what their neighbors did, so that if any lunatics were at large, one might know and avoid them.

(Note: The following samples use MLA-style documentation, but each incorrect example would be equally incorrect if the documentation were another style.)

Incorrect citation:

Eliot observes, "Women were expected to have weak opinions; but the great safeguard of society and of domestic life was, that opinions were not acted upon."

(This is incorrect because no page number is cited. The page number where the quotation appears must be included in a parenthetical reference.)

Correct citation:

Eliot observes, "Women were expected to have weak opinions; but the great safeguard of society and of domestic life was, that opinions were not acted upon" (3).

Incorrect citation:

Eliot notes that even a beautiful woman from a good family with a respectable income might be considered a poor prospect for marriage if gentlemen discovered that her beliefs were likely to make them uncomfortable in any way.

(This paraphrase is incorrect because no page number is given. Paraphrases and summaries require in-text citations just as quotations do.)

Correct citation:

Eliot notes that even a beautiful woman from a good family with a respectable income might be considered a poor prospect for marriage if gentlemen discovered that her beliefs were likely to make them uncomfortable in any way (3).

Incorrect citation:

In the nineteenth century, a woman could be "expected to have weak opinions; but the great safeguard of society and of domestic life was, that opinions were not acted upon" (3).

(This information is impossible for a reader to track down because the author's name, a necessary link to the works cited page, is missing.)

Correct citation:

In the nineteenth century, as Eliot says, a woman could be "expected to have weak opinions; but the great safeguard of society and of domestic life was, that opinions were not acted upon" (3).

Incorrect citation:

Dorothea is clearly an unusual woman, and Eliot emphasizes "her love of extremes, and her insistence on regulating life according to notions which might cause a wary man to hesitate before he made her an offer, or even might lead her at last to refuse all offers" (5).

(This is an incorrect citation because the page number given is wrong.)

Correct citation:

Dorothea is clearly an unusual woman, and Eliot emphasizes "her love of extremes, and her insistence on regulating life according to notions which might cause a wary man to hesitate before he made her an offer, or even might lead her at last to refuse all offers" (3).