TY  - BOOK
AU  - Elderton, William Palin , Sir
AU  - Johnson, Norman Lloyd , Sir
TI  - Systems of frequency curves
SN  - 0521073693
AV  - QA273.E5 1969 
PB  - Cambridge U.P.
KW  - Frequency curves
KW  - QA
N1  - Based on the 4th ed. of Elderton's Frequency curves and correlation; Bibliography: p. 202-205
ER  -