[1] Masaru Tominaga. Specht's ratio and logarithmic mean in the Young inequality [J]. Mathematical inequalities & applications 2004, 1(1). [2] Kahlig P., Matkowski J.. FUNCTIONAL EQUATIONS INVOLVING THE LOGARITHMIC MEAN [J]. Zeitschrift fur Angewandte Mathematik und Mechanik 1996, 7(7). [3] PITTENGER A O. The logarithmic mean in variables [J]. Amer Math Monthly 1985, 92(02). [4] STOLARSKY K B. Generalizations of the logarithmic means [J]. Math Magazine 1975, 48. [5] KOUBA O. New bounds for the identric mean of two arguments [J]. JIPAM J Inequal Pure Appl Math 2008, 9(03). [6] BURK F. The geometric logarithmic and arithmetic mean inequality [J]. Amer Math 1987, 94(06). [7] QI F, CUO B N. An inequality between ratio of the extended logarithmic and ratio of the exponential means [J]. Taiwanese J Math 2003, 7(02). [8] CARLSON B C. The logarithmic mean [J]. Amer Math 1972, 79. [9] CHU Yuming, ZONG Cheng, WANG Fendi. Optimal convex combination bounds of Seiffert and geometric means for the arithmetic mean [J]. Journal Math Inequal 2011, 5(03).