Cited in the article (and open access):

[1] Einstein, von Frisch and the honeybee: a historical letter comes to light

Adrian G. Dyer1,2, Andrew D. Greentree3, Jair E. Garcia1, Elinya L. Dyer4, Scarlett R. Howard5 & Friedrich G. Barth ORCID:orcid.org/0000-0001-9195-435X6 Journal of Comparative Physiology A (2021)

[1] https://link.springer.com/article/10.1007/s00359-021-01490-6

For the similarly minded: This is literally about the navigational capabilities of birds and bees.