KOHOUTEK, Rudolf. Theoretical and practical aspects of difficulties. In ŘEHULKA, Evžen. SCHOOL AND HEALTH 21(1), VOLS 2. 1st ed. Brno: Masarykova univerzita, 2006, p. 863-896, 33 pp. ISBN 978-80-7315-119-5.
KOHOUTEK, Rudolf. Theoretical and practical aspects of difficulties. In School and health 21. První. Brno: Nakladatelství PAIDO, Brno, 2005, p. 507 - 530, 23 pp. ISBN 80-7315-119-7.