中国科学院数学与系统科学研究院期刊网
Symplectic Matrix and Fundamental Forms of Self-Adjoint Boundary Conditions for Differential Operators of Order Four
Jiao Jiao WU, Jiong SUN, Jia Hui YU
Acta Mathematica Sinica, Chinese Series . 2016, (1): 47 -56 .  DOI: 10.12386/A2016sxxb0005