World futures.

v.17-18 (1981-82); v.18-19 (1982-84); v.19-21 (1983-85); v.20-21 (1984-85); v.22 (1986); v.23:1-2 1987; v.23:3 1987; v.24:1-4 1987; v.22-23 (1986-88); v.24-25 (1987-88); v.23:4 1988; v.25:1-2 1988; v.25:3-4 1988; v.26-27 (1989); v.26 no.1 1989; v.26 no.2-4 1989; v.27 no.1 1989; v.27 no.2-4 1989; v.28-29 (1990); v.28 no.1-4 1990; v.29 no.1 1990; v.29 no.3 1990; v.29 no.4 1990; v.30 no.1-2 1990; v.30-31 (1990-91); v.30 no.3 1991; v.30 no.4 1991; v.31 no.1 1991; v.31 no.2-4 (1991); v.32 (1991); v.34 1992; v.39-40 1994