NSCA estimates necessity with the NCA engine and sufficiency with
SCAtools. Please cite NSCA, the two packages it delegates to, and the
underlying NCA method.

  Chan Y (2026). _NSCA: Necessary and Sufficient Condition Analysis_. R
  package version 0.4.5.

A BibTeX entry for LaTeX users is

  @Manual{,
    title = {NSCA: Necessary and Sufficient Condition Analysis},
    author = {Young Chan},
    year = {2026},
    note = {R package version 0.4.5},
  }

  Chan Y (2026). _SCAtools: Direction-Aware Sufficiency Condition
  Analysis_. R package.

A BibTeX entry for LaTeX users is

  @Manual{,
    title = {SCAtools: Direction-Aware Sufficiency Condition Analysis},
    author = {Young Chan},
    year = {2026},
    note = {R package},
  }

  Dul J (2016). “Necessary Condition Analysis (NCA): Logic and
  Methodology of 'Necessary but Not Sufficient' Causality.”
  _Organizational Research Methods_, *19*(1), 10-52.
  doi:10.1177/1094428115584005
  <https://doi.org/10.1177/1094428115584005>.

A BibTeX entry for LaTeX users is

  @Article{,
    title = {Necessary Condition Analysis (NCA): Logic and Methodology of 'Necessary but Not Sufficient' Causality},
    author = {Jan Dul},
    journal = {Organizational Research Methods},
    year = {2016},
    volume = {19},
    number = {1},
    pages = {10--52},
    doi = {10.1177/1094428115584005},
  }