The Google Ngram Viewer or Google Books Ngram Viewer is an online search engine that charts the frequencies of any set of search strings using a yearly count of n-grams found in sources printed between 1500 and 2019 in Google's text corpora in English, Chinese (simplified), French, German, Hebrew, Italian, Russian, or Spanish.
correspondence
diaries
early works to 1800
interviews
pamphlets
periodicals
personal narratives
sources
oral histories
wills
probate records
sermons
church records and registers