Loughlin J, Quinn S, Rivero E, Wong J, Huang J, Kralstein J. Tegaserod and the risk of cardiovascular ischemic events: an observational cohort study. J Cardiovasc Pharmacol. 2010 Jun;15(2):151-7.
Williams VSL. The "unbiased" anchor: bridging the gap between DIF and item bias. Appl Meas Educ. 1997;10(3):253-67. doi: 10.1207/s15324818ame1003_4
Dubrey SW, Gnanasakthy A, Stein WK, Song JG, Hardman T, Hynd J, Noble MI. Enoximone in chronic stable angina: a double-blind placebo-controlled cross-over trial. J Cardiovasc Pharmacol. 1994 Apr;23(4):532-8.