@ARTICLE{Eastwood:87,
 AUTHOR = "James W. Eastwood",
 TITLE = "Orthovec:  A {REDUCE} Program for {3-D} Vector Analysis
in Orthogonal Curvilinear Coordinates",
 JOURNAL = "Comp. Phys. Commun.",
 YEAR = 1987, VOLUME = 47, NUMBER = 1, PAGES = "139-147", MONTH = "October"}

@ARTICLE{Eastwood:91,
 AUTHOR = "James W. Eastwood",
 TITLE = "{ORTHOVEC:} version 2 of the {REDUCE} program for {3-D} vector
analysis in orthogonal curvilinear coordinates",
 JOURNAL = "Comp. Phys. Commun.",
 YEAR = 1991, VOLUME = 64, NUMBER = 1, PAGES = "121-122", MONTH = "April"}

@BOOK{Speigel:59,
  AUTHOR = "M . Speigel",
  TITLE = "Vector Analysis",
  PUBLISHER = "Scheum Publishing Co.", YEAR = 1959}