Phase transitions.

v.67no.1(1998), v.67no.2(1998), v.67no.3(1998), v.68no.1(1999), v.68no.2(1999), v.68no.3(1999), v.68no.4(1999), v.69no.1(1999), v.69no.2(1999), v.69no.3(1999), v.69no.4(1999), v.70no.1(2000), v.70no.2(2000), v.70no.3(2000), v.70no.4(2000), v.71no.1(2000), v.71no.2(2000), v.71no.3(2000), v.71no.4(2000), v.72no.1(2000), v.72no.2(2000), v.72no.3(2000), v.72no.4(2000), v.73no.1/2(2001), v.73no.3(2001), v.73no.4(2001), v.74no.1/2(2001), v.74no.3(2001), v.74no.4(2001), v.75no.1/2(2002), v.75no.3(2002), v.75no.4/5(2002), v.75no.6(2002), v.75no.7/8(2002), v.76no.1/2(2003), v.76no.3(2003), v.76no.4/5(2003), v.76no.6(2003), v.76no.7(2003), v.76no.8(2003), v.76no.9/10(2003), v.76no.11(2003), v.76no.12(2003), v.77no.1/2(2004), v.77no.3(2004), v.77no.4(2004), v.77no.5/7(2004), v.77no.8/10(2004), v.77no.11(2004), Indexes: UN2(1981/2) U9(1987) U13(1989) UN27-33(1992) U45-51(1994)