To cite spsur in publications use:

Lopez F, Minguez R, Mur J (2020). “ML versus IV estimates of spatial SUR models: evidence from the case of Airbnb in Madrid urban area.” Annals of Regional Science, 64(2), 313–347.

Corresponding BibTeX entry:

  @Article{,
    title = {ML versus IV estimates of spatial SUR models: evidence
      from the case of Airbnb in Madrid urban area},
    author = {Fernando Lopez and Roman Minguez and Jesus Mur},
    journal = {Annals of Regional Science},
    year = {2020},
    volume = {64},
    number = {2},
    pages = {313--347},
  }