References
- Andrews , D. F. , Bickel , P. J. , Hampel , F. R. , Huber , P. J. , Rogers , W. H. and Tuckey , J. W. 1972 . Robust Estimates of Location , NJ , Princeton : Princeton University Press .
- Jaeckel , L. B. 1971 . Some flexible estimates of location . Ann. Math. Statist , 42 : 1540 – 1552 .