RT Journal Article SR Electronic(1) A1 Trogstad, L A1 Ung, G A1 Hagerup-Jenssen, M A1 Cappelen, I A1 Haugen, I L A1 Feiring, B YR 2012 T1 The Norwegian immunisation register – SYSVAK JF Eurosurveillance VO 17 IS 16 SP 20147 OP DO https://doi.org/10.2807/ese.17.16.20147-en UL https://www.eurosurveillance.org/content/10.2807/ese.17.16.20147-en