綠色新政David. Where are the Greens in the Green New Deal?. 進步 (雜誌). 2019-03-23 [2019-12-14]. (原始内容存档于2019-05-28). Gustafson, Abel; Rosenthal, Seth A.; Ballew, Matthew
最简分数see Laudal, Olav Arnfinn; Piene, Ragni, The Legacy of Niels Henrik Abel: The Abel Bicentennial, Oslo, June 3-8, 2002, Springer: 155, 2004 [2016-07-08]