Image credits:
- Spring: Benjamin Gimmel [GFDL or CC-BY-SA-3.0], via Wikimedia Commons
- Summer: By Peng (talk · contribs) (Own work) [GFDL or CC-BY-SA-3.0], via Wikimedia Commons
- Autumn: By Jean-Pol GRANDMONT (Own work) [CC BY-SA 3.0, GFDL or CC BY 3.0], via Wikimedia Commons
- Winter: By Petritap (Own work) [CC BY-SA 3.0 or GFDL], via Wikimedia Commons
