lingvokalendaroj
Most of my links here were outdated, and the Language Calendars domain is now for sale.
So... Here's an appropriate search at Amazon to get you started:
Living Language Calendar
Students of German should also visit
Bücherstube,
which carries (monolingual) Abreißkalendar and Wandkalendar.
21 Septembro 2013 modifita, de Ailanto verkita.