Reference

H. Pleijel, K. Ojanperä, H. Danielsson, E. Sild, J. Gelang, G. Wallin, L. Skärby, G. Sellden (1997): Effects of Ozone on Leaf Senescence in Spring Wheat - Possible Consequences for Grain Yield. – Phyton, Annales Rei Botanicae, Horn – 37_3: 227 - 232.