@misc{1147046, author = {Stefan Leigh and N Alan Heckert}, title = {Graphical analysis of the CCRl Portland cement proficiency sample database (samples 1-72):}, year = {1994}, month = {1994-01-01 05:01:00}, publisher = {, National Institute of Standards and Technology, Gaithersburg, MD}, doi = {https://doi.org/10.6028/NIST.IR.5387}, language = {en}, }