1ST OBSERVATION OF BACKBENDING IN AN ACTINIDE NUCLEUS - SPRENG, W; AZGUI, F; EMLING, H; GROSSE, E; KULESSA, R; MICHEL, C; SCHWALM, D; SIMON, RS; WOLLERSHEIM, HJ; MUTTERER, M; THEOBALD, JP; MOORE, MS; et al. (Physical Review Letters, 1983)