Starr et al. (1991):	4
Sininger et al. (1995):	2
Berlin et al. (1996):	2
Konradsson. (1996):	3
Picton et al. (1998):	2
Starr et al. (1998):	2
Miyamoto et al. (1999):	4
Lee et al. (2001):	4
Rance et al. (2004):	14
Zeng et al. (in press):	9