A mid-term analysis of progress toward international biodiversity targets. - Tittensor DP; Walpole M; Hill SL; Boyce DG; Britten GL; Burgess ND; Butchart SH; Leadley PW; Regan EC; Alkemade R; Baumung R; Bellard C; et al. (Science (New York, N.Y.), 2014)