Getting at the Quark Mass Matrices
  We present a class of Ansatze for the up and down quark mass matrices which leads approximately to: |V_{us}| \sim \sqrt{m_d / m_s}, |V_{cb}| \sim m_s / m_b, and |V_{ub} / V_{cb}| \sim \sqrt{m_u / m_c}. Sizes of the Kobayashi-Maskawa matrix elements are controlled solely by quark mass ratios. In particular, we introduce no other small parameter and our results do not rely on delicate cancellation. 
K. Harayama, N.Okamura, A. I. Sanda, and Z.Z.Xing (Nagoya Univ.)