sentences:  It receives waters from a number of small streams to its left and passes through the communes of Olivola and between Vignale Monferrato and Frassinello Monferrato.At Roncaglia, it is joined at the left by a second branch whose main source is in the hills near Ottiglio; this second branch has been joined by streams rising in Sala Monferrato, Cella Monte, and Rosignano Monferrato.From the right, it receives streams arising in Camagna Monferrato and Conzano.