Which Renaissance sculptors influenced the relief-like style of Fra Filippo Lippi’s altarpieces?

The relief-like style observed in the altarpieces of Fra Filippo Lippi—particularly in works such as the Barbadori Altarpiece—was influenced by the sculptural techniques of Donatello and Jacopo della Quercia.1

Lippi’s paintings from this period incorporate a pictorial effect of bas-relief, which he rendered more evident through the use of line, directly echoing the aesthetic qualities found in the works of these two prominent Renaissance sculptors.1