References are the simplest and most direct indication about the quality of papers that are submitted to journals. For that reason, pay particular attention in the correct writing of references of your article, in order to improve its quality and increase its publication chances. Moreover, apply faithfully the writing guidelines about references of the journal in which you are going to submit your article. Usually, failure to apply the writing guidelines of the journals is also accompanied by articles of low quality. The Vancouver system, also known as Arithmetic system is applied in most journals. In this case, references are numbered consecutively according to the order that they first appear in the text. Successive count is achieved with arabic numbers. At the end of the article, a list of references is cited according to the order that references appeared in text. In Harvard system, for each reference, author’s names and publication’s year are cited in article’s text. At the end of the article, a list of references is cited according to the alphabetic order of authors. Particular attention needs for plagiarism, which is defined as stealing an author’s work or ideas and using them as your own. Copying partially an entire sentence or paragraph of an author without the corresponding reference is considered to be plagiarism.