noun
a document, etc. that contains information obtained by research or observation, not taken from other books, etc.
—compare secondary source
noun
a document, etc. that contains information obtained by research or observation, not taken from other books, etc.
—compare secondary source
Oxford Advanced Learner's English Dictionary. Оксфордский английский словарь для изучающик язык на продвинутом уровне. 2005