Rocha, Manuel. <br/><br/>
Observation of dams, methods and apparatus used in Portugal- / Manuel Rocha, J. Laginha Serafin, A.F. de Silveira. 

 - Lisboa, Portugal : Laboratorio Nacional de Engenharia Civil 
 - 28 p. 
 - Technical paper; No.104 / Laboratorio Nacional de Engenhari-a Civil .