Energetic proton observations at 1 and 5 AU 1. January-September 1997 - Lario, D; Marsden, RG; Sanderson, TR; Maksimovic, M; Sanahuja, B; Balogh, A; Forsyth, RJ; Lin, RP; Gosling, JT (JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS, 2000)