• Brown, W. V. & Johnson, SK. C. (1962). The fine structure of the grass guard cell. Am. J. Bat., 49, 110.
  • Kaufman, P. B., Petering, L. B., Jocum, C. S. & Baic, D. (1970). Ultrastructural studies on stomata development in internodes of Avena saliva. Am. J. Bot., 57, 33.
  • Miroslavov, E, A. (1966). Electron microscope studies of stomata of the leaf of rye, Secale cereale L, Bot. Zh., Kyyiv, 51 (translated from Russian), 446.
  • Thomson, W. W. & Journett, R. de (1970), Studies on the ultrastructure of the guard cells of Opuntia. Am. J. Bot., 57, 309.
  • Whatley, J. M. (1971). Ultnsstmctural changes in thloroplasrs of Phttseolus vulgaris during development under conditions of nutrient deficiency. New Phytol, 70, 725.
  • Willmer, M. C. & Mansfield, T. A. (1970). Further observations on cation-stimulated opening in isolated epidermis, New Phytol., 69, 639.