Fortunato, E., V. Assuncao, A. Marques, A. Goncalves, H. Aguas, L. Pereira, I. Ferreira, FMB Fernandes, R. J. C. Silva, and R. Martins. "Electronic, Optoelectronic, Spintronic and Ferroelectric Materials-ZnO: Ga Thin Films Produced by RF Sputtering at Room Temperature: Effect of the Power Density." Materials Science Forum. Vol. 455. Aedermannsdorf, Switzerland: Trans Tech Publications, 1984-,  2004. 12-15.