Secondary sources refer to content that is first reported in another source. In scholarly work, it is recommended to cite primary sources directly rather than citing secondary sources. Secondary sources should only be cited sparingly, for instance, when the original work is out of print, unavailable, or available only in a language that you do not understand. If you must cite a secondary source, provide an entry for the secondary source in the reference list and identify the primary source in the text, writing “as cited in” the secondary source that you used. If the year of publication of the primary source is known, also include it in the text citation. For example, if you read a work by Lyon et al. (2014) in which Rabbitt (1982) was cited, and you were unable to read Rabbitt’s work yourself, cite Rabbitt’s work as the original source, followed by Lyon et al.’s work as the secondary source. Only Lyon et al.’s work appears in the reference list 1.
Secondary citations should be avoided as much as possible because they can lead to inaccuracies and errors in your work. When you cite a secondary source, you are relying on someone else’s interpretation of the original work, which may not be accurate or complete. Additionally, secondary sources can create a chain of citations that can be difficult to trace back to the original source, leading to confusion and errors. Therefore, it is always better to find and cite the primary source directly, unless it is not available or accessible 1.