Strutton DR, Farkouh RA, Earnshaw SR, Hwang S, Theidel U, Kontodimas S, Klok R, Papanicolaou S. Cost-effectiveness of 13-valent pneumococcal conjugate vaccine: Germany, Greece, and The Netherlands. J Infect. 2012 Jan 1;64(1):54-67.
Nguyen USDT, Rothman KJ, Demissie S, Jackson DJ, Lang JM, Ecker JL. Transfers among women intending a birth center delivery in the San Diego birth center study. J Midwifery Womens Health. 2009 Mar 1;54(2):104-10.