Skills Earth Sciences


The sources you use for your work must be traceable for the reader. To ensure this, a few rules on how to refer properly to the source you have used. To keep a text readable, the full source information should be listed at the end of your essay/article. This is called the reference list or bibliography. The information that must be provided in this list slightly depends on the kind of source you use:

  • Name of the author(s)
  • Title of the article
  • Title of the journal
  • Year of publication
  • Volume and/or issue
  • Page number
  • Name of author(s)
  • Title of book
  • Year of publication
  • Place of publication
  • Publisher
  • Digital Object Identifier (DOI), or
  • Uniform Resource Locator (URL)


There are different styles to cite sources within the text in use, varying from journal to journal. In general, geoscientific texts use the APA-style (Using sources – Citing – LibGuides at Utrecht University ( This implies that in the text, you mention the author(s) and year of publication. These two things are enough to link the citation with the correct reference in your bibliography. If your source only has one or two authors, you mention both names in text. If there are more than two authors, you mention only the first author and add the abbreviation ‘et al.’.


For more information on citing, see Referring to your sources – Citing – LibGuides at Utrecht University (