  The analysis of experiments at nuclear reactors where inverse beta decay
reaction positron spectrum was measured at different distances from reactor
core is presented here. It was found that there appear three enclosed zones of
neutrino oscillation parameters when joint analysis is applied on the
${\Delta}m^{2}-\sin^{2}2{\theta}$ plane. The parameters that found are
partially crossed with similar regions originating from other non reactor
experiments where they observed neutrino oscillations having unusual mass
parameter about 1 eV^2 and amplitude about 0.04. Confidence level for observed
regions achieves the value of 99.9%.
