Primary sources or original research are based on an experiment or a study of a topic. They include a methodology section if an experiment was set up and conducted, a results or discussion section, and a conclusion. A secondary source would be an article commenting on or analyzing the original research.
Hermit Crab on the Beach by Eric Heupel on flikr, CC BY-NC 2.0.
Find reference resources, journal articles, books, websites and specialised resources related to zoology