00566nam a2200169Ia 4500003000900000008004100009040001600050080002400066110003300090245012200123260005000245300000900295500001900304650003400323650001800357650002100375IN-BaIIA211028s9999 xx 000 0 eng d cIIA Library a083.7:69.028.8bISI aIndian Standards Institution 0aIndian standard safety requirements for floor and wall openings railings and toe boardscIndian Standards Institution aNew DelhibIndian Standards Institutionc1969 a10p. aIS 4912 : 1968 a Civil Engineering-Standards a Standards  aNASA Thesaurus