参考资料:
https://africageographic.com/
https://bbc.com/earth/story/20150518-the-epic-history-of-rhinos
https://iucnredlist.org/species/6553/18493355#population
https://livescience.com/27439-rhinos.html
https://panda.org/discover/knowledge_hub/endangered_species/rhinoceros/q_a_joseph_okori/
https://rhinosos.com/myths-about-rhino-horn-dont-buy-it/
http://rhinoresourcecenter.com/
https://theconversation.com/we-asked-people-in-vietnam-why-they-use-rhino-horn-heres-what-they-said-116307
https://ucmp.berkeley.edu/mammal/mesaxonia/perissodactyla.html