@article{NUMA_1993__65_4_133723,
     author = {Borislav Bojanov},
     title = {Interpolation by periodic splines with {Birkhoff} knots.},
     journal = {Numerische Mathematik},
     pages = {63--76},
     publisher = {mathdoc},
     volume = {65},
     number = {4},
     year = {1993},
     zbl = {0795.41002},
     url = {http://geodesic.mathdoc.fr/item/NUMA_1993__65_4_133723/}
}