CircleTimes 
CircleTimes[x]
displays as .
CircleTimes[x,y,…]
displays as .
Details

- CircleTimes[x,y,…] has no built-in meaning.
is by default interpreted as CircleTimes[x,y].
can be entered as \[CircleTimes] or
c*
.
Examples
Basic Examples (1)
Wolfram Research (1996), CircleTimes, Wolfram Language function, https://reference.wolfram.com/language/ref/CircleTimes.html.
Text
Wolfram Research (1996), CircleTimes, Wolfram Language function, https://reference.wolfram.com/language/ref/CircleTimes.html.
CMS
Wolfram Language. 1996. "CircleTimes." Wolfram Language & System Documentation Center. Wolfram Research. https://reference.wolfram.com/language/ref/CircleTimes.html.
APA
Wolfram Language. (1996). CircleTimes. Wolfram Language & System Documentation Center. Retrieved from https://reference.wolfram.com/language/ref/CircleTimes.html