To cite pseval in publications use:

Michael C. Sachs and Erin E. Gabriel (2016). An Introduction to Principal Surrogate Evaluation with the pseval Package. The R Journal: 8(2); 277-292. URL https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5774631/.

Corresponding BibTeX entry:

  @Article{,
    title = {An introduction to principal surrogate evaluation with the
      pseval package},
    author = {{Sachs} and Michael C and {Gabriel} and Erin E},
    journal = {The R journal},
    volume = {8},
    number = {2},
    pages = {277--292},
    year = {2016},
    publisher = {NIH Public Access},
    url = {https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5774631/},
  }