Aman, Nelia Verzosa Construction safety practices of contractors in Metro Vigan : effect to productivity / Nelia Verzosa-Aman. - Laoag City : [s.n.], 2015. - xiv, 93 pages : illustration ; 28 centimeter. Bibliography: pages 66-67. Subjects--Topical Terms: Construction safety. Dewey Class. No.: TH 690 Am1c 2015