Frankl - Founder of Logotherapy.
Längle - Founder and President of the Society for
Logotherapy and Existential Analysis in Vienna.
Spinelli - Academic Dean of the School of Psychotherapy
and Counselling at Regent's College, London, UK.
du Plock - He is a Senior Lecturer with the School of
Psychotherapy and Counselling at Regent’s College in
van Deurzen - Founder and Director of The New School of
Psychotherapy and Counselling.
K. Zeig - President of the Milton Erickson Foundation,
T. P. Wong - Founder and President of the International
Network on Personal Meaning.
May - Existential Therapy.
Rogers - Client-Centred Therapy.
Adler - Individual Psychology.
Jung - Analytical Psychology.
Fabry - Past President of the Viktor Frankl Institute
Lukas - Founder of the South German Institute of Logotherapy.