N-modal steady water waves with vorticity
  The problem for two-dimensional steady gravity driven water waves with vorticity is investigated. Using a multidimensional bifurcation argument, we prove the existence of small-amplitude periodic steady waves with an arbitrary number of crests per period. The role of bifurcation parameters is played by the roots of the dispersion equation. 
Vladimir Kozlov, Evgeniy Lokharu
math.AP math-ph math.MP