Table 2
Selected literature results by year of publication
Year of publication
Quantity of references used
2018
1
2017
8
2016
4
2015
3
2014
3
2013
4
2012
1
2011
1
2009
2
2007
1
2005
2
2003
1
2002
2
2001
1
2000
1
1999
1
1997
1
1996
1
1994
1
Undated
7