He went on to develop a theory of double-valued formal groups that led to the calculation of cobordism rings of complex manifolds having symplectic coverings and to the explicit construction of what are now known as  Buchstaber manifolds.
Continuing from his work, he developed a theory concerning double-valued formal groups that enabled calculations of cobordism rings for complex manifolds equipped with symplectic coverings. This also resulted in the construction of what are known today as Buchstaber manifolds.