Sehgal, J. L. <br/><br/>
Cavity Walls  / 
J. L. Sehgal ; National Buildings Organisation, Ministry of Works, Housing and Supply, Govt. of India 
 - New Delhi :  National Buildings Organisation ,  [n.d.] 
 - 18 p. :  ill. ;  25 cm. 
 - Tegchnical Information series / National Buildings Organisation;  no.20 .
 - National Buildings Organisation  Tegchnical Information series;  no.20 .
<br/><br/><label>Dewey Class. No.: </label>690