Can anyone help me locate Donato James Summa? He got his Ph.D from Pennsylvania State University in 1981; his thesis was on geometry proof. I'm hoping to get some more information about the data he collected.
For those interested, the complete citation is:
Summa, Donato James (1981). The effects of proof format, problem structure, and the type of given information on achievement and efficiency in geometric proof. Ph.D. diss., Pennsylvania State University.