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See https://water.usgs.gov/nrp/gwsoftware/sutra/sutra.html for a model overview, the source code, documentation, and software download.
Burow K., Constanz J., Fujii R., 2005, Heat as a tracer to estimate organic carbon loads from a restored wetland. Groundwater 43(4):545-556. https://doi.org/10.1111/j.1745-6584.2005.0055.x
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