For the 2nd study, I was not able to pull up a full text version [sigh], but I did find a critique cited in a later article:
Assessing Cognitive and Psychomotor Performance Under Long-Term Treatment with Transdermal Buprenorphine in Chronic Noncancer Pain Patients. Anesthesia & Analgesia. 105(5):1442-1448, November 2007.
In contrast to our hypothesis are the findings of Jamison et al. (15) who compared psychomotor function of patients with noncancer pain receiving transdermal fentanyl or controlled-release oxycodone in a crossover design and reported no significant differences between the two opioids. However, the informational value of the results is limited by the fact that the authors performed only two paper tests.
If anyone has the full text versions of these articles, please give a shout out.
Holla.