Shear-induced platelet aggregation can be mediated by VWF released from platelets, as well as by exogenous large or unusually large VWF multimers, requires adenosine diphosphate, and is resistant to aspirin - Moake,J.L.; Turner,N.A.; Stathopoulos,N.A.; Nolasco,L.; Hellums,J.D. (Blood, 1988)