Institution: | 1.Universidad Nacional Autónoma de México, Centro de Ciencias Matemáticas, UNAM, Campus Morelia, 58190, Morelia, Mich, Mexico ;2.Department of Mathematics, Rice University, 6100 Main St., Houston, TX, 77005-1827, USA ;3.Walailak University, 222 Tumbon Thaiburi, Thasala, Nakhon Si Thammarat, 80160, Thailand ; |