1. Primot, L. April 1988.‘Friction welding. A very favourable balance’April, 39–44. CETIM-Informations No. 105
2. Primot, L. June 1988.‘Friction welding. A very favourable balance (II)’June, 31–42. CETIM-Informations No. 106
3. AFNOR Standard NF A35-551: ‘Special purpose unalloyed and alloyed structural steels for case hardening’
4. AFNOR Standard NF A35-552: ‘Special purpose unalloyed and alloyed structural steels for heat treatment’
5. June 1986. June, AFNOR Standard NF A35-550: ‘Indication of the machinability of special purpose unalloyed and alloyed structural steels for case hardening and for heat treatment’