@article{MABA_2004_18_3-4_a4,
     author = {G. Chobanov and I. Dimovski},
     title = {Extension of the {Duhamel} {Principle} for {Time-Nonlocal} {Boundary} {Value} {Problems}},
     journal = {Mathematica balkanica},
     pages = {259},
     publisher = {mathdoc},
     volume = {18},
     number = {3-4},
     year = {2004},
     url = {http://geodesic.mathdoc.fr/item/MABA_2004_18_3-4_a4/}
}