Abstract

Get full access to this article
View all access options for this article.
References
1.
1.
Armitage P
: Statistical Methods in Medical Research.
Oxford : Blackwell Scientific Publications , 1971 , pp 59 –72 .
2.
2.
Steel RGD
,
Torrie JH
: Principles and Procedures of Statistics.
New York : McGraw-Hill , 1980 , pp 523 –32 .
3.
3.
Osborn JF
: Statistical Exercises in Medical Research.
Oxford : Blackwell Scientific Publications , 1979 , pp 15 –18 , 103–104.
4.
4.
Cary NC
: SAS Procedure Guide. Release 6.03 edition. SAS Institute Inc. , 1988 , p 406 .
