Durham, Sharon. „Making Spinach with Low Oxalate Levels“. AgResearch Magazine (January 2017). United States Department of Agriculture. Nuoroda tikrinta 26 June 2017. „The scientists analyzed oxalate concentrations in 310 spinach varieties—300 USDA germplasm accessions and 10 commercial cultivars. "These spinach varieties and cultivars displayed oxalate concentrations from 647.2 to 1286.9 mg/100 g on a fresh weight basis," says Mou.“