To cite bpca in publications use:

Faria, J.C & Demétrio, C. G. B (2013).bpca: Biplot of multivariate data based on Principal Components Analysis.ESALQ, USP, Brasil.

Lots of time and effort were invested in creating bpca. Please, cite it when using it together with R. See also ‘citation()’ for citing R.

Corresponding BibTeX entry:

    title = {bpca: Biplot of Multivariate Data Based on Principal
      Components Analysis.},
    author = {José Cláudio Faria and Clarice Garcia Borges Demétrio and
      Ivan Bezerra Allaman},
    organization = {UESC and ESALQ},
    address = {Ilheus, Bahia, Brasil and Piracicaba, Sao Paulo,
    year = {2013},