See also the following link:
https://onlinelibrary.wiley.com/doi/10.1002/jpln.19240030304
Littauer, F. (1924), Zersetzung des Harnstoffes im Boden. Z. Pflanzenernaehr. Dueng./A, 3: 165-179. https://doi.org/10.1002/jpln.19240030304
See also the following link:
https://onlinelibrary.wiley.com/doi/10.1002/jpln.19240030304
Littauer, F. (1924), Zersetzung des Harnstoffes im Boden. Z. Pflanzenernaehr. Dueng./A, 3: 165-179. https://doi.org/10.1002/jpln.19240030304