REFERENCES
- Carraro L. and Lombardo G., 1976.—Tapetal ultrastructural changes during pollen development. II. Studies on Pelargonium zonale and Kalanchoë obtusa. Caryologia, 29: 339–344.
- Guérin P., 1926.—Le développement de l'anthère chez les Centianacées. Bull. Soc. Bot. France, 73: 5–18.
- Lombardo G. and Carraro L., 1976.—Tapetal ultrastrucluial changes during pollen development. I. Studies on Antirrhinum maius. Caryologia, 29: 113–125.