@article{eckardt:1930:ppb,
     title = {The penetration of a potential barrier by electrons},
    author = {Eckart, Carl},
   journal = {Phys. Rev.},
    volume = {35},
    number = {11},
     pages = {1303–1309},
      year = {1930},
       doi = {10.1103/PhysRev.35.1303},
 publisher = {American Physical Society},
     zblno = {56.0750.03}}