The reference citation style described here is a version of the "Author, Date" scientific style, adapted from Hansen (1991) and the Council of Biology Editors (1994).
Harnack & Kleppinger (2000) have adapted "CBE style" to cite and document online sources.
Additionally, if the author's name is not mentioned in the sentence, you would format your citation with the author's name followed by a comma, followed by a shortened title of the work, followed, when appropriate, by page numbers: Common sense and ethics should determine your need for documenting sources.
You do not need to give sources for familiar proverbs, well-known quotations or common knowledge.
You should acknowledge a source any time (and every time) you use a fact or an idea that you obtained from that source.
Thus, clearly, you need to cite sources for all direct quotations.
The author's name may appear either in the sentence itself or in parentheses following the quotation or paraphrase, but the page number(s) should always appear in the parentheses, not in the text of your sentence.
For example: Wordsworth stated that Romantic poetry was marked by a "spontaneous overflow of powerful feelings" (263).
In MLA style, referring to the works of others in your text is done by using what is known as parenthetical citation.
This method involves placing relevant source information in parentheses after a quote or a paraphrase.