Agricultural Statistics (1994). The Ministry of Agriculture and land Reclamation, Economic Affairs Sector.
Agricultural Statistics (1984). The Ministry of Agriculture and land Reclamation, Economic Affairs Sector.
Baily, N; I. (1994). Statistical methods in biology. Cambridge U. Press, 3rd edition, N. Y., USA.
Buser, M.D.; M.L. Stone; G.H. Bruswitz; N.O. Moness and D.P. Whitelock. (1999). Thin-layer drying of marigold flowers and flower components for petals removal. Transactions of the ASAE. 42 (5):1367-1373
C.L.A.C. (2000). The Central Laboratory of Agricultural Climate, Douky, Giza, Egypt.
Charlchat, J.C; R.P. Garry and A. Michet. (1991). Chemical composition of essential oil of Calendula officinalis. Flower and Frgrance Journal. 6(3): 189-192. (CF Horticultural Abstract. 1992. 62 (4): 325-389).
E.E.D.C. (1998). Egyptian Exports Development Center, Giza, Egypt.
Hall, C.W. and P. E. Pear. (1980). Drying and storage of agricultural crops, AVI, Publishing Company, Inc., West Port conc., USA.
Henderson, S.M. and R. L. Perry. (1976). Agriculture process engineering. Published by the AVI Publishing Company, Inc., Library of Congress, Washington, USA.
Kramer, A and B. Twigg (1974). Quality control for the food industry. The AVI Pub. Co. Inc., West port. Connecticut. USA.
Othman, A. A. (1996). Utilization of solar energy in drying of some medicinal plants. PH. D. Th. Fac. Ag., Fayoum, Cairo University, Egypt.