  Several observed anomalies in neutrino oscillation data can be explained by a
hypothetical fourth neutrino separated from the three standard neutrinos by a
squared mass difference of a few eV^2. We show that this hypothesis can be
tested with a PBq (ten kilocurie scale) 144Ce or 106Ru antineutrino beta-source
deployed at the center of a large low background liquid scintillator detector.
In particular, the compact size of such a source could yield an
energy-dependent oscillating pattern in event spatial distribution that would
unabiguously determine neutrino mass differences and mixing angles.
