  The distribution $N(x)$ of citations of scientific papers has recently been
illustrated (on ISI and PRE data sets) and analyzed by Redner [Eur. Phys. J. B
{\bf 4}, 131 (1998)]. To fit the data, a stretched exponential ($N(x) \propto
\exp{-(x/x_0)^{\beta}}$) has been used with only partial success. The success
is not complete because the data exhibit, for large citation count $x$, a power
law (roughly $N(x) \propto x^{-3}$ for the ISI data), which, clearly, the
stretched exponential does not reproduce. This fact is then attributed to a
possibly different nature of rarely cited and largely cited papers. We show
here that, within a nonextensive thermostatistical formalism, the same data can
be quite satisfactorily fitted with a single curve (namely, $N(x) \propto
1/[1+(q-1) \lambda x]^{q/{q-1}}$ for the available values of $x$. This is
consistent with the connection recently established by Denisov [Phys. Lett. A
{\bf 235}, 447 (1997)] between this nonextensive formalism and the
Zipf-Mandelbrot law. What the present analysis ultimately suggests is that, in
contrast to Redner's conclusion, the phenomenon might essentially be one and
the same along the entire range of the citation number $x$.
