@article{li:1991:grz,
     title = {Generalized {R}iemann $\zeta{}$-function regularization and {C}asimir energy
           for a piecewise uniform string},
    author = {Li, Xinzhou  and Shi, Xin  and Zhang, Jianzu},
   journal = {Phys. Rev. D},
    volume = {44},
    number = {2},
     pages = {560–562},
      year = {1991},
       doi = {10.1103/PhysRevD.44.560},
 publisher = {American Physical Society}}