To cite ltmle in publications use:

Lendle SD, Schwab J, Petersen ML, van der Laan MJ (2017). “ltmle: An R Package Implementing Targeted Minimum Loss-Based Estimation for Longitudinal Data.” Journal of Statistical Software, 81(1), 1–21. doi: 10.18637/jss.v081.i01.

Corresponding BibTeX entry:

  @Article{,
    title = {{ltmle}: An {R} Package Implementing Targeted Minimum
      Loss-Based Estimation for Longitudinal Data},
    author = {Samuel D. Lendle and Joshua Schwab and Maya L. Petersen
      and Mark J. {van der Laan}},
    journal = {Journal of Statistical Software},
    year = {2017},
    volume = {81},
    number = {1},
    pages = {1--21},
    doi = {10.18637/jss.v081.i01},
  }