1. Albersheim, P., Muhletaler, K. & Frey-Wyssling, A., 1960. Stained pectin as seen in the electron microscope.J. biophys, biochem. Cytol. 8: 501–516.
2. Allen, R. F., 1923. Cytological studies on infection of Baart, Kanred and Mindum wheats byPuccinia graminis tritici forms III and XIX.J. agric. Res. 26: 571–604.
3. Ammann, A., 1952. Uber die Bildung von Zellulase bei pathogenen Mikroorganismen.Phytopath. Z. 18: 416–446.
4. Anderson, J. W., 1968. Extraction of enzymes and sub-cellular organelles from plant tissues.Phytochem. 7: 1973–1988.
5. Artschwager, E. F., 1927. Wound periderm formation in the potato as affected by temperature and humidity.J. agric. Res. 35: 995–1000.