Head-butting

References

1. ^ . Oxford English Dictionary (online ed.). Oxford University Press. doi:10.1093/OED/4595875797. (Subscription or participating institution membership required.)
2. ^ 56.
3. ^ 2024.
4. ^ 2026.
5. ^
6. ^
7. ^
8. ^
9. ^ 31. ISBN . Archived from the original on 11 May 2018 2017.
10. ^.
11. ^.
12. ^
13. ^
14. ^
15. ^
16. ^.
17. ^ . Official Rules 2012-2013. National Hockey League 2019.
18. ^
19. ^ 2017.; Kilfoyle, Peter (2000-01-01). Left Behind: Lessons from Labour's Heartland. Politico's. p. 230. ISBN .
20. ^ 2017.