Providing info for future viewer:
Osterlind's 13 Steps to Mentalism (4 DVDs)
http://www.penguinmagic.com/p/6696
VS:
13 Steps To Mentalism (6 DVDs)
http://www.penguinmagic.com/p/3763
The 6 DVD set is Richard Osterlind following Corinda's 13 Steps to Mentalism.
The 4 DVD set is Richard doing his own material, not really having anything to do with Corinda.
Two different animals.