1. Hammare och borr.;Dahl;Jernkont. Annlr,1932
2. Studies on the percussive deep hole drilling of rocks;Takaoka;J. Min. metall. Inst. Jpn.,1956
3. Energy transfer in percussive drilling;Fairhurst,1958
4. On the longitudinal impact I–III;Fischer;Appl. scient. Res.,1959
5. On longitudinal impact I–III;Fischer;Appl. scient. Res.,1959