  Recently Zhang et al. [2008] presented a statistical study of sizes and
relative geoeffectiveness of ICMEs (bodies of magnetic clouds) and preceding
sheaths for 46 events responsible for intense (Dst < -100 nT) geomagnetic
storms in 1996-2005 in which only a single ICME was responsible for generating
the storm. Here we would like to comment several results and conclusions of
this paper.
