Ford, C. L. <br/><br/>
polarographic method for the direct determination of alumin-ium oxide in portland cement / by C. L. Ford and Lorrayne L-eMar. 

 - Chicago : Portland Cement Association, Research Laboratories 
 - 12 p. 
 - Bulletin 28 / Portland Cement Association .
<br/><br/> "Authorized reprint from copyrighted ASTM Bulletin, No. 157-, March, l949".