There are many ways to employ Parenthetical Referencing in a paper, thus making it sometimes inconsistent or ineffective as a referencing system. In this work we list and explain a set of 21 guidelines for a consistent and effective use of Parenthetical Referencing (also known as Harvard Style Referencing). We followed very closely APA's Manual of Style, but added important modifications taken from selected online guides (the main three guides being Anglia Ruskin University, University of Leeds and the University of South Australia). We explain in detail how to reference blogs, websites, youtube videos, wikipedia pages, as well as other kinds of online media. Our main intention is to provide useful and up-to-date examples of Parenthetical Referencing being applied to some of the most familiar works in the colombian economic literature. This note is aimed towards helping undergraduate economics' students and junior researchers by serving them as a handful guide for writing their research work.