Notes
1-6 http://en.wikipedia.org/wiki/1900 (1901-1957)
7 http://en.wikipedia.org/wiki/1958
8 http://en.wikipedia.org/wiki/1959
9 http://en.wikipedia.org/wiki/1960
10 http://en.wikipedia.org/wiki/1961
11 http://en.wikipedia.org/wiki/1962
12 http://en.wikipedia.org/wiki/1963
13 http://en.wikipedia.org/wiki/1964
14 http://en.wikipedia.org/wiki/1965
15 http://en.wikipedia.org/wiki/1966
16 http://en.wikipedia.org/wiki/1967
17 www.nrlc.org/abortion/facts/abortiontimeline.html
18 http://en.wikipedia.org/wiki/1968
19 http://en.wikipedia.org/wiki/1969
20 Man, Myth, and Magic: An Illustrated Encyclopedia of the Supernatural
21 http://en.wikipedia.org/wiki/1970
22 www.nrlc.org/abortion/facts/abortiontimeline.html
23 http://en.wikipedia.org/wiki/1971
24 http://en.wikipedia.org/wiki/1972
25 www.nrlc/org/abortion/facts/abortiontimeline.html
26 http://en.wikipedia.org/wiki/1973
27 www.nrlc/org/abortion/facts/abortiontimeline.html