The marks of reference to the source works are given in brackets, in italics. Blanksby et al., 2004; Clothier et al., 2000a; Clothier et al., 2000b; Blanksby et al., 1995; Hay, 1986; Hodgkinson and Blanksby, 1996; Cossor et al., 1999; Lyttle and Mason, 1997; Lyttle et al., 1999a; Lyttle et al., 1998; Takahashi et al., 1983. |