1           2006-01-21.66  
2           1990-02-22.33  Wisniewski et al. (1997) 
3           1990-02-23.29  Wisniewski et al. (1997) 
4           2008-09-05.38  
5           2009-01-30.13  
6           2009-02-02.14  
7  1997-06-03--2011-11-27  Lowell