To cite sparsepca in publications use:

Erichson, N. B., Zheng, P., Manohar, K., Brunton, S. L., Kutz, J. N., and Aravkin, A. Y. (2020). Sparse Principal Component Analysis via Variable Projection. SIAM Journal on Applied Mathematics, 80(2), 977-1002. https://doi.org/10.1137/18M1211350

Corresponding BibTeX entry:

  @Article{,
    title = {Sparse Principal Component Analysis via Variable
      Projection},
    author = {N. Benjamin Erichson and Peng Zheng and Krithika Manohar
      and Steven L. Brunton and J. Nathan Kutz and Aleksandr Y.
      Aravkin},
    journal = {SIAM Journal on Applied Mathematics},
    year = {2020},
    volume = {80},
    number = {2},
    pages = {977--1002},
    doi = {10.1137/18M1211350},
    url = {https://doi.org/10.1137/18M1211350},
  }