TY  - BOOK
AU  - Spear,Mary Eleanor
TI  - Practical charting techniques
AV  - HA31 .S67
U1  - 001.4226 
PY  - 1969///]
CY  - New York
PB  - McGraw-Hill
KW  - Statistics
KW  - Graphic methods
N1  - Bibliography: p. 369-371
ER  -