APA (7th ed.) Citation

Bai, Z. (2007). The upper and lower solution method for some fourth-order boundary value problems. Nonlinear analysis, 67(6), 1704-1709. https://doi.org/10.1016/j.na.2006.08.009

Chicago Style (17th ed.) Citation

Bai, Zhanbing. "The Upper and Lower Solution Method for Some Fourth-order Boundary Value Problems." Nonlinear Analysis 67, no. 6 (2007): 1704-1709. https://doi.org/10.1016/j.na.2006.08.009.

MLA (9th ed.) Citation

Bai, Zhanbing. "The Upper and Lower Solution Method for Some Fourth-order Boundary Value Problems." Nonlinear Analysis, vol. 67, no. 6, 2007, pp. 1704-1709, https://doi.org/10.1016/j.na.2006.08.009.