@article{Szajna:2016,
  author  = "W. Szajna and P. Lechocka",
  title   = "Evaluation of the two methods of determining bulk density of sand: tapping fork test and vibrating table test",
  journal = "Roads and Bridges - Drogi i Mosty",
  volume  = "Vol. 15",
  pages   = "5--20",
  year    = "2016",
}