1. Apud, E., 1989. Human biological methods for ergonomics research in forestry. In: Apud, E., Bostrand, L., Mobbs, I.D., Strehlke, B. (Eds.), Guidelines on Ergonomic Study in Forestry. International Labour Office, Geneva.
2. Apud, E., Valdes, S., 1994. Physical workload and output for planting on grounds with different slopes. Proceedings of International IUFRO/NEFU/FOA Seminar on Forest Operations Under Mountainous Conditions with special attention to Ergonomics, Accessibility and Environmental Protection, Harbin, P.R. of China.
3. Textbook of Work Physiology;Åstrand,1986
4. Threshold values for the Botsball;Beshir;Ergonomics,1982
5. A wet globe thermometer for environmental heat measurement;Botsford;American Industrial Hygiene Association Journal,1971