Six years of short-spaced monitoring of the and , 28SiO maser emission in evolved stars
J. Alcolea, J. R. Pardo, V. Bujarrabal, R. Bachiller, A. Barcia, F. Colomer, J. D. Gallego, J. Gómez-González, A. del Pino, P. Planesas, S. del Río, A. Rodríguez-Franco, A. del Romero, M. Tafalla and P. de Vicente