Inge Bethke, Piet Rodenburg. The initial meadows. Journal of Symbolic Logic, 75(3):888-895, 2010. [doi]
@article{BethkeR10, title = {The initial meadows}, author = {Inge Bethke and Piet Rodenburg}, year = {2010}, url = {http://projecteuclid.org/euclid.jsl/1278682205}, researchr = {https://researchr.org/publication/BethkeR10}, cites = {0}, citedby = {0}, journal = {Journal of Symbolic Logic}, volume = {75}, number = {3}, pages = {888-895}, }