请帮查找一下这几篇文章 万分感谢 1、Factors affecting the stability of rennin 《Journal of Dairy Science》 Mickelson R 1963 / 46 / P 613 2、Rapid and large scale isolation of chymosin by pepstatin-aminohexylagarose 《Agricultural and Biological Chemistry》 Hideyuki K 1987 / 42 / P 2227-2231 3、皱胃酶提取工艺的研究 Extraction of calf rennet [中国乳品工业 China Dairy Industry] 卢蓉蓉 , 张国农 , 方民 , 黄艳艳 4、小牛皱胃酶提取技术的研究 Studies on extraction technology of calf rennet [西北农林科技大学学报(自然科学版) Journal of Northwest Sci-Tech University of Agriculture and Forestry] 张富新 5、羔羊皱胃酶提取工艺研究 Studies on the extracting techniques of kid rennet [河南农业科学 Journal of Henan Agricultural Sciences] 赵胜娟 , 陈树兴 , 张富新 , ZHAO Sheng-juan