In citations, how to find out if it's a compound name?
The convention, inasmuch as one exists, is:


  Write the name the way the individual wants it to be written.


For example, one of my co-authors has four names: 


  (First Name) (Middle Name) (Adopted Married Name) (Given Last Name) 


but chooses to use 


  (First Initial). (Middle Name) (Adopted Initial). (Last Name)


as his "formal" academic name. 

As a more concrete example of this phenomenon, this is a significant issue with a lot of British folks, who eschew the hyphen in a "double-barreled" last name. For instance, you'd cite:


  Vaughan Williams, Ralph. The Lark Ascending. London: Oxford University Press (2005). 


and not 


  Williams, Ralph V. The Lark Ascending. London: Oxford University Press (2005). 


In such cases, you just need to look up exactly how the author writes his or her name, and follow that trend. Google Scholar can be a good source of such information; Web of Science and other citation-tracking sites are often better.

The most useful method of all would be to find "self-citations": works where the author cites his or her own work. How the name is written under those circumstances should be the most unambiguous statement.