To cite biwavelet in publications use:

Tarik C. Gouhier, Aslak Grinsted, Viliam Simko (2019). R package biwavelet: Conduct Univariate and Bivariate Wavelet Analyses (Version 0.20.19). Available from https://github.com/tgouhier/biwavelet

Corresponding BibTeX entry:

  @Manual{,
    title = {R package {biwavelet}: Conduct Univariate and Bivariate
      Wavelet Analyses},
    author = {Tarik C. Gouhier and Aslak Grinsted and Viliam Simko},
    year = {2019},
    note = {(Version 0.20.19)},
    url = {https://github.com/tgouhier/biwavelet},
  }