Sazhin A. “Phototrophic and Heterotrophic Nano- and Microorganisms of Sea Ice and Sub-Ice Water in Guba Chupa (Chupa Inlet), White Sea, in April 2002”. Polar Research, vol. 23, no. 1, June 2004, pp. 11-18, doi:10.3402/polar.v23i1.6261.