1. Affinity, efficacy, and receptor classification: Is the classical theory still useful?;Colquhoun,1987
2. Use of null equations, based on classical and ternary models of drug action, to classify receptors and receptor-effector systems even if some of the agonists and antagonists available have additional actions on tissues;MacKay,1987
3. Definition of pharmacological receptors;Kenakin;Pharmacol Rev,1992
4. Classification based on ligand binding: On the chemical meaning of ligand affinity in studies of drug receptor interactions;Weinstein,1987
5. Antagonists with negative intrinsic activity at δ-opioid receptors coupled to GTP-binding proteins;Costa,1989