Generalized Weierstrass formulae for surfaces in four-dimensional space R-4
are used to study (anti)self-dual rigid string configurations. It is shown
that such configurations are given by superminimal immersions into R-4. Ex
plicit formulae for generic (anti)instantons are presented. Particular clas
ses of surfaces are also analyzed. (C) 1999 Elsevier Science B.V. All right
s reserved.