@inbook{Spitze1998,
author = {Spitze, G. and Ward, R.A.},
title= {Gender variations},
year = {1998},
editor = {Szinovacs, M.E.},
booktitle = {Handbook on grandparenthood},
address = {Westport, CT},
publisher = {Greenwood Press},
pages = {113--127},
}