@article{TAM_2020_47_2_a6,
     author = {Aleksandar Obradovi\'c and Slavi\v{s}a \v{S}alini\'c and Aleksandar Tomovi\'c},
     title = {Free vibrations of planar serial frame structures in the case of axially functionally graded materials},
     journal = {Theoretical and applied mechanics},
     pages = {221 - 239},
     publisher = {mathdoc},
     volume = {47},
     number = {2},
     year = {2020},
     url = {http://geodesic.mathdoc.fr/item/TAM_2020_47_2_a6/}
}