[en] The isotopes ^237,238,240Cf were produced in irradiations of ^204,206,207Pb targets with ³⁶S ions. At bombarding energies close to the Coulomb barrier two or three neutrons were evaporated from the compound nuclei ^240,242,243Cf. Cross-sections were on the order of a few hundred nanobarns. For the isotope ²⁴⁰Cf a spontaneous fission branching of 0.015 ±0.002 was determined. The new isotope ²³⁶Cm was produced by α decay of ²⁴⁰Cf and identified by α-α correlations. It decays with an α -decay energy of (6954± 20)keV and a half-life of (410±50) s. For the first time, the α decay of ²³⁷Cf was observed having an energy of (8081±20) keV. For the isotope ²³³Cm a half-life of (23⁺¹³_-6) s was measured for first time. Spontaneous fission of ^237,238Cf was confirmed and mass-excess values of the nuclei ²³⁶Cm and ^237,240Cf were determined. (orig.)