Вертикальный ритм

www.alistapart.com/articles/settingtypeontheweb
www.clagnut.com/blog/1942
www.jameswhittaker.com/blog/article/em-based-layouts-vertical-rhythm-calculator
meyerweb.com/eric/thoughts/2006/02/08/unitless-line-heights
topfunky.com/baseline-rhythm-calculator
www.markboulton.co.uk/journal/comments/incremental_leading