source of a quotation; citation source; reference source
Refers to the original source from which a quote, data, or information is taken. Common in academic, journalistic, and online contexts.
In a paper, you must clearly indicate the source of your citations.
The source of this data is government statistics.
参考文献 refers to a list of references or bibliography, whereas 引用元 points to the specific source of a particular quotation.
Compound of 引用 (citation, quotation) and 元 (source, origin).