(1984). Physics and development, No.4.
Dyfyniad Arddull ChicagoPhysics and Development, No.4. International centre for theoretical physics, 1984.
Dyfyniad MLAPhysics and Development, No.4. 1984.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.