“…In more than one dimension, the concepts of order statistics and ranks are more involved and several definitions have been proposed in Mahalanobis (1936), Tukey (1975), Brown (1983), Oja (1983), Liu (1988Liu ( ,1990, Small (1990), Gordaliza (1991), Singh(1991), Donoho and Gasko (1992), Liu and Singh (1993), Cuesta-Albertos, Gordaliza and Matrán (1997) and Fraiman and Meloche (1999).…”