發送短信

數:

提供者:

CAPTCHA:

  ______   __   __   _____      _____     _  _   
 /_   _//  \ \\/ // |  __ \\   |  ___||  | \| || 
   | ||     \ ` //  | |  \ ||  | ||__    |  ' || 
  _| ||      | ||   | |__/ ||  | ||__    | .  || 
 /__//       |_||   |_____//   |_____||  |_|\_|| 
 `--`        `-`'    -----`    `-----`   `-` -`

Please enter what you see:

發送短信 : Which robust versions of sample variance and sample covariance are most appropriate for econometrics: Symmetry-based analysis