中国科学院数学与系统科学研究院期刊网
Bang-Bang Principle of Time Optimal Controls and Null Controllability of Fractional Order Parabolic Equations
Qi LU
Acta Mathematica Sinica . 2010, (12): 2377 -2386 .  DOI: 10.1007/s10114-010-9051-1