TY  - JOUR
AU  - B. S. Kruglikov
TI  - Some classification problems in four-dimensional  geometry: distributions, almost complex structures, and generalized Monge--Ampere equations
JO  - Sbornik. Mathematics
PY  - 1998
SP  - 1643
EP  - 1656
VL  - 189
IS  - 11
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/SM_1998_189_11_a2/
LA  - en
ID  - SM_1998_189_11_a2
ER  -