Measurements of D0 meson strong-phase parameters in quantum-correlated [Formula: see text] decays by the CLEO collaboration are presented. These measurements play an important role in the determination of the unitarity triangle angle γ/ϕ3 from B-meson decays. Measurements of the strong-phase parameters for D0 → K0π+π-, D0 → K0 K+ K-, D0 → K- π+ π0, and D0 → K- π+ π+ π- decays are described along with their impact on the determination of γ/ϕ3.