1. Mathematic coupling of data: a common source of error;Archie;Ann. Surg.,1981
2. Misleading statistics: predialysis norepinephrine and its change after hemodialysis;Boer;Nephron,1990
3. Medical Statistics. A Commonsense Approach;Campbell,1993
4. The balloon rules for a rough estimate of the correlation coefficient;Chatillon;Amer Stat,1984
5. Statistical Power Analysis for Behavioral Sciences;Cohen,1988