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Dyfyniad Arddull ChicagoNational School Boards Association, William George Bruce, William Conrad Bruce, and Susanna Cocroft. The American School Board Journal. Milwaukee, Wis.: Bruce Pub. Co.
Dyfyniad MLANational School Boards Association, et al. The American School Board Journal. Bruce Pub. Co.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.