@inbook{inbookcfc0357d,
title   = {Covariance analysis by means of the least squares method},
author = {Vanin, Vito Roberto and Helene, Otaviano Augusto Marcondes},
year = {2007},
publisher = {IAEA},
journal   = {Update of X Ray and Gamma Ray Decay Data Standards for Detector Calibration and Other Applications}
}