Modjeski, R. (1921). Report to the Delaware River Bridge Joint Commission of the states of Pennsylvania and New Jersey on the bridge over the Delaware River connecting Philadelphia, Pa. & Camden, N.J. [S.l.]: Delaware River Bridge Joint Commission.

Modjeski, Ralph. Report to the Delaware River Bridge Joint Commission of the States of Pennsylvania and New Jersey On the Bridge Over the Delaware River Connecting Philadelphia, Pa. & Camden, N.J. [S.l.]: Delaware River Bridge Joint Commission, 1921.

Modjeski, Ralph. Report to the Delaware River Bridge Joint Commission of the States of Pennsylvania and New Jersey On the Bridge Over the Delaware River Connecting Philadelphia, Pa. & Camden, N.J. [S.l.]: Delaware River Bridge Joint Commission, 1921.