A circumpolar monitoring framework for polar bears - Vongraven, Dag; Aars, Jon; Amstrup, Steven; Atkinson, Stephen; Belikov, Stanislav; Born, Erik; DeBruyn, T.D.; Derocher, Andrew; Durner, George; Gill, Michael; Lunn, Nicholas J.; Obbard, Martyn; et al. (Ursus, 2012)