@article{SF_1996__53_2_135467,
     author = {H. Oka},
     title = {Second order linear {Volterra} integrodifferential equations.},
     journal = {Semigroup forum},
     pages = {25--43},
     publisher = {mathdoc},
     volume = {53},
     number = {2},
     year = {1996},
     zbl = {0856.45016},
     url = {http://geodesic.mathdoc.fr/item/SF_1996__53_2_135467/}
}