APA Citation 


APA uses the author's last name, and the published year, or page number; example: (thapa magar, 2012, p.16), 'pp' for more than a page. 

Example:
-Darwin theory(1859) explains about the evolution "can act only by very short and slow
steps" (p.510).

-About the evolution process "can act only by very short and slow
steps" (Darwin, 1859p.510).

MLA Citation 

In MLA, author's last name and page number in parentheses; but at the last part of paper publisher should provide detail reference of every source you have cited. 

Example

 -Darwin explains about the evolution "can act only by very short and slow
steps" (510).

-About the evolution process "can act only by very short and slow
steps" (Darwin 510).

Reference

https://owl.purdue.edu/owl/research_and_citation/apa_style/apa_formatting_and_style_guide/in_text_citations_the_basics.html