Hedstrom, Richard O. <br/><br/>
Influence of mortar and block properties on shrinkage crack-ing of masonry walls / by Richard O. Hedstrom, Albert Litvi-n and J. A. Hanson. 

 - Skokie, Illinois. : atories, Development Department 
 - 24 p. 
 - Bulletin D131 / Portland Cement Association, Research and D-evelopment Laboratories, Development Department. .