Reed, P. (2006). Effect of required response force on rats’ performance on a VI+ schedule of reinforcement. Learning & Behavior, 34(4), pp. 379-386. doi:10.3758/BF03193203

Reed, Phil. "Effect of Required Response Force On Rats’ Performance On a VI+ Schedule of Reinforcement." Learning & Behavior 34, no. 4 (2006): 379-386.

Reed, Phil. "Effect of Required Response Force On Rats’ Performance On a VI+ Schedule of Reinforcement." Learning & Behavior 34.4 (2006): 379-386.