Ackley S., Wadhams P., Comiso J. C., and Worby A. P. “Decadal Decrease of Antarctic Sea Ice Extent Inferred from Whaling Records Revisited on the Basis of Historical and Modern Sea Ice Records”. Polar Research, vol. 22, no. 1, Jan. 2003, pp. 19-25, doi:10.3402/polar.v22i1.6439.