To cite rtmpt in publications use:

  Hartmann, R., Johannsen, L., & Klauer, K. C. (2020). rtmpt: An R
  package for fitting response-time extended multinomial processing
  tree models. Behavior Research Methods, 52(3), 1313-1338. doi:
  10.3758/s13428-019-01318-x

A BibTeX entry for LaTeX users is

  @Article{,
    title = {{rtmpt}: {An R} package for fitting response-time extended multinomial processing tree models},
    author = {{Raphael Hartmann} and {Lea Johannsen} and {Karl Christoph Klauer}},
    journal = {Behavior Research Methods},
    year = {2020},
    volume = {52},
    number = {3},
    pages = {1313--1338},
    doi = {10.3758/s13428-019-01318-x},
    note = {R package version 2.1-3},
  }

  Hartmann, R., & Klauer, K. C. (2020). Extending RT-MPTs to enable
  equal process times. Journal of Mathematical Psychology, 96, 102340.
  doi: 10.1016/j.jmp.2020.102340

A BibTeX entry for LaTeX users is

  @Article{,
    title = {Extending {RT}-{MPTs} to enable equal process times},
    author = {{Raphael Hartmann} and {Karl Christoph Klauer}},
    journal = {Journal of Mathematical Psychology},
    year = {2020},
    volume = {96},
    pages = {102340},
    doi = {10.1016/j.jmp.2020.102340},
  }
