“…It is noteworthy (Olkhovsky & Recami, 1968;1969) that, as we are going to see, operator (68a) is nothing but the usual Newton-Wigner operator, while (68b) can be interpreted (Gallardo et al, 1967b;Ka'lnay, 1966;Ka'lnay & Toledo, 1967;Olkhovsky et al, 1967;Olkhovsky & Recami, 1968;1969;Toller, 1999) as yielding the sizes of the localization-region (an ellipsoid) via its average values over the considered wave-packet. Let us underline that the previous formalism justifies from the mathematical point of view the treatment presented in papers like (Baldo & Recami, 1969;Gallardo et al, 1967b;Ka'lnay, 1966;Ka'lnay & Toledo, 1967;Olkhovsky et al, 1967;Recami, 1970). We can split (Olkhovsky & Recami, 1968;1969) the operatorẑ into two bilinear parts, as follows: (Baldo & Recami, 1969;Gallardo et al, 1967b;Ka'lnay, 1966;Ka'lnay & Toledo, 1967;Olkhovsky et al, 1967;Recami, 1970;Recami et al, 1983) space of wave packets.…”