On the integrability and quasi-periodic wave solutions of the Boussinesq equation in shallow water Pan-Li Ma, Shou-Fu Tian, Jian-Min Tu and Mei-Juan Xu Eur. Phys. J. Plus, 130 5 (2015) 98 Published online: 27 May 2015 DOI: 10.1140/epjp/i2015-15098-0