For 2017, the Vikings have following referees available:

National Level
Daniel Triebsch / Nico Piveteau

Regional Level
Luke Ireland / Jack Gallagher
Todd Anderson / Sam Keegan
Maddy Hazelton / Bridget Ireland

Local Level
Harry Ireland / Paul Ireland

Handball Rules
Rules of the game (here as a pdf)
Simplified Handball rules for beginners (here as a pdf)
Handball rules wonderfully explained in a short youtube clip (here)