Lotka-Volterra dynamics under periodic influence
  Lotka Volterra model and its modified forms have long become a major area of interest for periodic motions in nonlinear systems with competitive species. The model given by Volterra shows that its periodicity is dependent on initial condition. This characteristics allows us to calculate the effect of periodic seasonal changes on population densities of different species 
Debabrata Dutta and J K Bhattacharjee