Google Books Ngram Viewer

Graph these comma-separated phrases:
case-insensitive
between and from the corpus with smoothing of .  
Search in Google Books:

1920 - 1933 1934 - 1993 1994 - 1999 2000 - 2004 2005 - 2008 authenticity English
1920 - 1930 1931 - 1987 1988 - 1995 1996 - 2002 2003 - 2008 authentic English

Run your own experiment! Raw data is available for download here.
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