To cite GOSemSim in publications use:

  Guangchuang Yu. Gene Ontology Semantic Similarity Analysis Using
  GOSemSim. In: Kidder B. (eds) Stem Cell Transcriptional Networks.
  Methods in Molecular Biology, 2020, 2117:207-215. Humana, New York,
  NY.

A BibTeX entry for LaTeX users is

  @Article{,
    title = {Gene Ontology Semantic Similarity Analysis Using GOSemSim},
    author = {Guangchuang Yu},
    journal = {Methods in Molecular Biology},
    shortjournal = {Methods Mol. Biol.},
    year = {2020},
    volume = {2117},
    pages = {207-215},
    pmid = {31960380},
    issn = {1940-6029},
    doi = {10.1007/978-1-0716-0301-7_11},
  }

  Guangchuang Yu, Fei Li, Yide Qin, Xiaochen Bo, Yibo Wu and Shengqi
  Wang. GOSemSim: an R package for measuring semantic similarity among
  GO terms and gene products. Bioinformatics 2010 26(7):976-978

A BibTeX entry for LaTeX users is

  @Article{,
    title = {GOSemSim: an R package for measuring semantic similarity among GO terms and gene products},
    author = {Guangchuang Yu and Fei Li and Yide Qin and Xiaochen Bo and Yibo Wu and Shengqi Wang},
    journal = {Bioinformatics},
    year = {2010},
    volume = {26},
    number = {7},
    pages = {976-978},
    pmid = {20179076},
    doi = {10.1093/bioinformatics/btq064},
  }