Liang Liang,  Fengchun Lei &  Fengling Li. (2021). Unstabilized Self-Amalgamation of a Heegaard Splitting along Disks.
            <i>Communications in Mathematical Research </i>. <i>32</i> (2).
            117-121.
         doi:10.13447/j.1674-5647.2016.02.04