There are several questions that arise in the preparation of a bibliography. It’s important that these issues are assumed through from the beginning to ensure that the data that must be presented is collected completely, avoiding duplication of effort and above all, inconsistency in the presentation of the reference list. Learning how to cite and reference the information used is fundamental, to avoid accusations of plagiarism (voluntary or involuntary).

It’s important to know:

  • How to present the reference of a journal article or a chapter in a book?
  • How to cite information taken from the internet?
  • What is the best way to list the set of references I have?
  • How do I link the citation I have in my text with the corresponding reference in the final bibliography?

The American Library Association-ALA presents - in summary form - several topics that give preliminary guidelines for the organization of a bibliography,

  • There are several ways to cite each of the different types of documents we intend to reference, because there are many rules on this matter, created by different entities and organizations.
  • Some of these rules have the "force of law" as the national norms for each country, applying the international norms in their absence.
  • However, scientific journals often require from Authors (for the publication of their articles) their own presentation formats, which in some cases have become very relevant, and may be considered alongside the standards mentioned above, such as the "Recommendations for the Conduct, Reporting, Editing, and Publication of Scholarly Work in Medical Journals".
  • Finally, it’s worth mentioning another important topic, which is how to present these references in a list, establishing a logical and coherent connection of this list (called "Bibliography, References", etc.) to the text of the work we are writing.

In short, "referencing" consists in identifying books, scientific articles and other documents used throughout the work, through citations (abbreviated form in the body of the text) and bibliography (detailed form at the end of the work).


Portuguese Norm - NP405

The Portuguese Institute for Quality, IPQ, is the national organization responsible for drafting standards that apply to various areas and sectors of activity.

Among the various standards that concern the sphere of "Documentation", the Portuguese Standard concerning bibliographic references is NP 405, edited in 4 distinct parts:

  • NP 405-1 – It establishes the models for bibliographic references of monographs, parts of monographs, journals, journal articles, standards, and patents. It must be used for printed documents.
  • NP 405-2 - It establishes the models of bibliographic references for non-book materials- posters, engravings, films, video, or sound recordings, etc.
  • NP 405-3 - It establishes the models of bibliographic references for unpublished documents- monographs and serial publications not published commercially, circulars, letters, manuscripts, manuscript music, cartographic materials.
  • NP 405-4 – It establishes the models of bibliographic references for electronic documents- databases, computer programs, electronic journals, journal articles, among others.

International Norm - AMA

The American Medical Association has created the American Medical Association Manual of Style, which is one of the most widely used in Medical Sciences and Biomedicine.

Since it is increasingly common to consult documents in electronic formats, there are multiple sites where this topic is dealt with on the internet. The National Library of Medicine- the entity responsible for Medline/Pubmed which can be consulted via the internet- has a document that mentions how to cite in Medicine.


A complementary issue of bibliographic citations is how to order the references and how to establish the correspondence between the text and the listed bibliography.

For this purpose, there are several styles (numeric) and (name, date), but it’s the academic institutions that define which styles to adopt.


As you search for books and scientific articles from various databases, you can organize your references using citation management software such as EndNote, Mendeley or Zotero.