To cite sparseLM in publications use:

  Lourakis M (2010). “Sparse Non-linear Least Squares Optimization for
  Geometric Vision.” In Daniilidis K, Maragos P, Paragios N (eds.),
  _Computer Vision - ECCV 2010: 11th European Conference on Computer
  Vision, Heraklion, Crete, Greece, September 5-11, 2010, Proceedings,
  Part II_, volume 6312 series Lecture Notes in Computer Science,
  43-56. doi:10.1007/978-3-642-15552-9_4
  <https://doi.org/10.1007/978-3-642-15552-9_4>.

A BibTeX entry for LaTeX users is

  @InProceedings{,
    title = {Sparse Non-linear Least Squares Optimization for Geometric Vision},
    author = {Manolis I. A. Lourakis},
    booktitle = {Computer Vision - ECCV 2010: 11th European Conference on Computer Vision, Heraklion, Crete, Greece, September 5-11, 2010, Proceedings, Part II},
    editor = {Kostas Daniilidis and Petros Maragos and Nikos Paragios},
    series = {Lecture Notes in Computer Science},
    volume = {6312},
    pages = {43-56},
    year = {2010},
    publisher = {Springer},
    address = {Berlin, Heidelberg},
    doi = {10.1007/978-3-642-15552-9_4},
  }