It has been proposed by Juha Kokko and Floyd Rector Jr. in 1972.1
Kokko, Juha P.; Rector Jr., Floyd C. (1972). "Countercurrent multiplication system without active transport in inner medulla". Kidney International. 2 (4): 214–23. doi:10.1038/ki.1972.97. PMID 4657922. https://doi.org/10.1038%2Fki.1972.97 ↩