- https://www.worldwildlife.org/stories/the-great-monarch-migration
- https://www.fws.gov/story/phenomenal-monarch-migration#:~:text=Timing is everything&text=Decreasing day length and temperatures,and travel 10 times farther.
- https://www.umassmed.edu/globalassets/reppert-lab/publications/cshreview2008.pdf
- https://pubmed.ncbi.nlm.nih.gov/26473314/
- https://www.fs.usda.gov/wildflowers/pollinators/Monarch_Butterfly/migration/index.shtml#:~:text=Monarchs roost for the winter,0 to 15 degrees Celsius.
- https://news.mongabay.com/2018/12/deforestation-and-mining-threaten-a-monarch-butterfly-reserve-in-mexico/
- https://www.sciencedirect.com/science/article/abs/pii/S0305750X21000322
- https://www.biologicaldiversity.org/news/press_releases/2018/monarch-butterfly-03-05-2018.php / https://oxfordre.com/latinamericanhistory/display/10.1093/acrefore/9780199366439.001.0001/acrefore-9780199366439-e-1084