Del 
Del[x]
displays as .
Examples
Basic Examples (1)
Wolfram Research (1996), Del, Wolfram Language function, https://reference.wolfram.com/language/ref/Del.html.
Text
Wolfram Research (1996), Del, Wolfram Language function, https://reference.wolfram.com/language/ref/Del.html.
CMS
Wolfram Language. 1996. "Del." Wolfram Language & System Documentation Center. Wolfram Research. https://reference.wolfram.com/language/ref/Del.html.
APA
Wolfram Language. (1996). Del. Wolfram Language & System Documentation Center. Retrieved from https://reference.wolfram.com/language/ref/Del.html