To cite package 'crossnma' in publications use:

  Hamza T, Schwarzer G, Salanti G (2024): crossnma: An R Package to
  Synthesize Cross-Design Evidence and Cross-Format Data Using Network
  Meta-Analysis and Network Meta-Regression. BMC Medical Research
  Methodology; 24: 169.

A BibTeX entry for LaTeX users is

  @Article{,
    title = {crossnma: An R Package to Synthesize Cross-Design Evidence and Cross-Format Data Using Network Meta-Analysis and Network Meta-Regression},
    author = {Tasnim Hamza and Guido Schwarzer and Georgia Salanti},
    journal = {BMC Medical Research Methodology},
    year = {2024},
    number = {24},
    pages = {169},
  }

DOI: 10.1186/s12874-023-02130-0