Key points are not available for this paper at this time.
& ) & E E Fr I hQ " "b F G s q " & & r s qt gT gS CG Pd "r he f Pe g P RX " h i j k X "r Pd fd lr R mT ni jd "b ed fo pd f ad lT g % g q Pq Rr "T n r Ps us ti pG Pr " T Wu wv xT
Ferrer‐i‐Cancho et al. (Sat,) studied this question.