Multiple soliton solutions and multiple complex soliton solutions for two distinct Boussinesq equations

We investigate two Boussinesq equations where the fourth-order terms come with minus and plus signs. We show that the Boussinesq equation with minus fourth-order term gives multiple soliton solutions, whereas the model with the plus fourth-order term gives multiple complex soliton solutions. We show that the two models are characterized by real and complex dispersion relations, respectively. Moreover, we derive other solitonic, singular, and periodic solutions for each model.