Search for a known article with Citation Linker.
The Citation Linker tool can be useful, but be advised: Simply typing in a partial Journal Title and the Article Title or Author Surname in WILL NOT WORK. This search tool is actually most sensitive to fields like Volume, Year and Page Number, so be sure to enter some or all of this information--as much as you have--if you want the Citation Linker to work.
Certain codes specific to the periodical or article are also very useful, if known. ISSN is the International Standard Serial Number, a unique eight-digit number used to identify a print or electronic periodical publication. It looks like this: 1756-2651. You may also search by DOI, or digital object identifier. Cites to those identifiers look like this: doi:10.1016/j.socnet.2010.04.003. You would search for the code following the doi: A PMID (also a search option below) is a PubMed identifier. An example looks like this: PMID: 21246529. Like a doi it is a unique number assigned to a citation, in this case, in the life sciences.