Mukhopadhyay, Nitis; Chattopadhyay, Bhargab - In: Statistical Papers 54 (2013) 3, pp. 827-837
It may not be an overstatement that one of the most widely reported measures of variation involves S <Superscript>2</Superscript>, the sample variance, which is also well-known to be alternatively expressed in the form of an U statistic with a symmetric kernel of degree 2 whatever be the population distribution function....</superscript>