1. Viewpoints on apornictic and sexual reproduction in angiosperms
2. BATTAGLIA E., 1963.—In: «Recent advances in the Embryology of Angiosperms» P. Maheshwari ed., International Society of Plant Morphologists, University of Delhi, 221–264.
3. BEDNARA J., 1978.—Bull. Soc. bot. Fr., 125, Actual, bot. 171–175.