c(
	person("Robert J.", "Hijmans", role = c("cre", "aut"),  email = "r.hijmans@gmail.com"),
	person("Charles", "Karney", role = "ctb", comment="GeographicLib"),	
	person("Ed", "Williams", role = "ctb"),
	person("Chris", "Vennes", role = "ctb"))
Spherical trigonometry for geographic applications. That is, compute distances and related measures for angular (longitude/latitude) locations.
Robert J. Hijmans [cre, aut],
  Charles Karney [ctb] (GeographicLib),
  Ed Williams [ctb],
  Chris Vennes [ctb]