PCM redirects here. For other uses, see PCM (disambiguation). Pulse-code modulation (PCM) is a method used to digitally represent sampled analog signals. It is the standard form of digital audio in computers, compact discs, digital telephony and other digital audio applications. In a PCM stream, the amplitude of the analog signal is sampled regularly at uniform intervals, and each sample is quantized to the nearest value within a range of digital steps.
1 As well as MLA, APA papers are also double-spaced with 1-inch margins on each side. 2  APA guidelines recommend you to use readable and clear font, such as Times New Roman, 12 pt.  The main distinction of APA style is a ârunning headâ at the top of each page.
Internal Documentation (in-text citations, parenthetical references) APA Publication Manual, sections 6.01-6.21 APA style uses the author-date system for citing references in the text of your paper. Each reference cited in the text will appear alphabetically in your reference list. A helpful chart of basic citation styles appears on page 177 in the APA Publication Manual. Direct quotations (APA Manual, p.170-171) In addition to the author and the date, direct quotations must also include the page. number (or paragraph number for non-paginated sources).