Ralf Hinze. The Bird Tree. Journal of Functional Programming, 19(5):491-508, 2009. [doi]
@article{Hinze09-0, title = {The Bird Tree}, author = {Ralf Hinze}, year = {2009}, doi = {10.1017/S0956796809990116}, url = {http://dx.doi.org/10.1017/S0956796809990116}, researchr = {https://researchr.org/publication/Hinze09-0}, cites = {0}, citedby = {0}, journal = {Journal of Functional Programming}, volume = {19}, number = {5}, pages = {491-508}, }