High-frequency polarity swings during the Gauss-Matuyama reversal from Baoji loess sediment - TianShui Yang; Masayuki Hyodo; ZhenYu Yang; ShiHong Zhang; Toshiaki Mishima; HuaiChun Wu; HaiYan Li; Yi Li; XingAn Shi; Kan Wang; YiMing Ma (Science China Earth Sciences, 2014)