1. Belling, J. 1921. On counting chromosomes in pollen-mother cells. Am. Nat. 55: 573–574.
2. Bir, S. S. and Cheema, P. 1994. Cytology of some members of genus Cyperus L. sect Juncellus Griseb. from North-Western India. Cyperaceae Newsl. 13: 9–12.
3. Bir, S. S., Cheema, P. and Sidhu, M. K. 1990. SOCGI plant chromosome number reports-IX. J. Cytol. Genet. 25: 137–139.
4. Bir, S. S., Cheema, P. and Sidhu, M. 1992. Chromosomal diversity in member of genus Cyperus Linn. from Punjab, North-West India-I. Section Kyllinga (Rottb.) Endl. J. Plant Sci. 8: 4–8.
5. Bir, S. S., Cheema, P. and Singh, C. P. 1996. Chromosomal analysis of sedges of Sangrur District, Punjab, North-West India. Bangladesh J. Bot. 25: 51–58.