Grudd, H, Briffa, KR, Gunnarson, BE, & Linderholm, HW (2000): «Swedish tree rings provide new evidence in support of a major, widespread environmental disruption in 1628 BC» i: Geophysical Research Letters27 (18): 2957–2960. Bibcode:2000GeoRL..27.2957G. doi:10.1029/1999GL010852.
Grudd, H, Briffa, KR, Gunnarson, BE, & Linderholm, HW (2000): «Swedish tree rings provide new evidence in support of a major, widespread environmental disruption in 1628 BC» i: Geophysical Research Letters27 (18): 2957–2960. Bibcode:2000GeoRL..27.2957G. doi:10.1029/1999GL010852.