JOURNAL OF MATHEMATICAL PHYSICS, cilt.37, sa.6, ss.3050-3061, 1996 (SCI-Expanded)
The preliminary classification of q(t)=f(q,q(x),q(xx),q(xxx)) is given. The results are compared with Fokas's symmetry and Mikhailov-Shabat-Sokolov formal symmetry approaches. (C) American Institute of Physics.