3Wilker J.B., E3301[J], The American Mathematical Monthly, 1989, 96(1):55.
4Sumner J. S., Jagers A. A., Vowe M., and Anglesio J., Inequalities involving trigonometric functions[J],The American Mathematical Monthly, 1991, 98(3):264 - 267.
二级参考文献2
1J.B. Wilker. E3306[J]. The American Mathematical Monthly,1989,96(1) :55.
2J.S. Sumner, A. A. Jagers,M. Vowe,and J. Anglesio Inequalities involving trigonometric function[J]. The American Mathematical Monthly, 1991,98 (3): 264-267.
3J. B. Wilker. E3301[J], The American Mathematical Monthly, 1989,96(1):55.
4J. S. Sumner, A. A. Jagers, Micheal Vowe, and jean Anglesio, Inequalities Involving Trigonometric Functions[J], The American Mathematical Monthly, 1991, 98(3):264-267.
