primary document; primary source
Technical term used in computing and information science for original documents or raw data, as opposed to secondary or tertiary sources.
In research, it is important to consult primary documents.
このデータベースには一次文献が多数収録されている。
This database contains many primary sources.
Compound of 一次 (primary, first-order) and 文献 (literature, documents). The term is a modern technical coinage, likely influenced by English 'primary document' or 'primary source'.