Hang in there, Linda! I've been down that road, as have a lot of your fellow
lactnetters; and you're right, slow steps may be frustrating but they get
you there. (How many cliches can I string together here?)

The AAP statement on BF'ing (Dec. 1997) says "Pediatricians are encouraged
to work actively toward eliminating practices that discourage breastfeeding
(eg, infant formula discharge packs...)".

Then there's always the WHO Code on the international marketing of
breastmilk substitutes: WHO 1981 , and WHO Protecting, Promoting, and
Supporting Breastfeeding: The special role of maternity services. WHO
1989:13-18

This is an old reference, and probably not the best for your purposes since
it deals more with the effects of providing a breast pump @ DC than the neg.
effects of formula sample packs (my reprint comes from the M____a br. pump
co., just as a hint to the bias): Claibourne, Christensen-Szalanski, Losch,
& Russell. Effect of discharge samples on duration of breastfeeding.
Pediatrics Vol. 90 No. 2, Aug. 1992, pp 233-237.  Compares women who rec'd a
DC pack including formula samples to those who re'd DC pack w/no form., but
with a br. pump: greater BF duration in group getting the pump (4.18 wks. vs
2.78 wks, mean)

Burgevin, Dougherty, & Kramer. Do infant formula samples shorten the
duration of breastfeeding? Lancet. 1983; 1:1148-1151. Well-ed. white women
in Montreal; more likely to be BFing @ 1 mo. if no DC sample of formula.

Frank,Wirtz, Sorenson, Heeren. Commercial discharge packs and breastfeeding
counseling: effects on infant feeding practices in a randomized trial.
Pediatrics. 1987;80:845-854.predominantly low-income non-white women in
Boston MA; no formula samples,  women who rec'd "research pack" (br. pads &
ed. materials) more likely to exclusively BF longer and to be still ptly BF
@ 4 mo. (vs. women who got nothing).

Seems to me I read a study more recently in JHL, but don't have it right at
my fingertips. (But look, I upped my organizing since that flurry of posts,
and I have these others right at my elbow!)

Good luck - you will get there, because you have right on your side! Cathy
Bargar, RN, IBCLC