The 17-volume Macropædia is the third part of the `` Encyclopædia Britannica '' ; the other two parts are the 12-volume `` Micropædia '' and the 1-volume `` Propædia '' .
The 17-book Macropædia is the third part of the `` Encyclopædia Britannica '' , and the other two parts are the 12-book `` Micropædia '' and the 1-book `` Propædia '' .