@article{10_2140_agt_2009_9_2041,
     author = {Yang, Guoqiu and Lei, Fengchun},
     title = {Amalgamations of {Heegaard} splittings in 3{\textendash}manifolds without some essential surfaces},
     journal = {Algebraic and Geometric Topology},
     pages = {2041--2054},
     year = {2009},
     volume = {9},
     number = {4},
     doi = {10.2140/agt.2009.9.2041},
     url = {http://geodesic.mathdoc.fr/articles/10.2140/agt.2009.9.2041/}
}