To cite lavaan.survey in publications use:

Daniel Oberski (2014). lavaan.survey: An R Package for Complex Survey Analysis of Structural Equation Models. Journal of Statistical Software, 57(1), 1-27. URL http://www.jstatsoft.org/v57/i01/.

Corresponding BibTeX entry:

  @Article{,
    title = {{lavaan.survey}: An {R} Package for Complex Survey
      Analysis of Structural Equation Models},
    author = {Daniel Oberski},
    journal = {Journal of Statistical Software},
    year = {2014},
    volume = {57},
    number = {1},
    pages = {1--27},
    url = {http://www.jstatsoft.org/v57/i01/},
  }