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1 Abrol, D. P., "Time and energy budgets of alfalfa pollinating bees Megachile nana Bingh and Megachile flavipes Spinola (Hymenoptera: Megachilidae)" 95 : 579-586, 1986
2 Schoner, T. W., "Theory of feeding strategies" 2 : 369-404, 1971
3 Hocking, B., "The intrinsic range and speed of flight of insects" 104 : 223-345, 1953
4 Schmid-Hempel, P., "The importance of handling time for flight directionality in bees" 15 : 303-309, 1984
5 Faegri, K., "The Principles of Pollination Ecology" Pergamon Press 1966
6 Waddington, K.D., "The Biology of Social Insects" Boulder Westview Press 24-27, 1982
7 Hickman, J. C., "Pollination by ants : a low-energy system" 184 : 1290-1292, 1974
8 Southwick, D., "Pimentel, Energy efficiency of honey production by bees" 31 (31): 730-732, 1981
9 Srinivasan, M. V., "Pattern recognition in the honeybee:Recent progress" 40 : 183-194, 1994
10 Pyke, G. H., "Optimal foraging: a selective review of theory and tests" 52 : 137-154, 1977
11 Krebs, J. R., "Optimal foraging. In: Behavioural Ecology -An evolutionary Approach" Blackwell Scientific Publications 1978
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18 Pyke, G. H., "Foraging Behaviour" 1980
19 Abrol, D. P., "Energy requirement and its harvest as determinant of foraging decisions of bees abstract no MP-002" 2010
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21 Abrol, D. P., "Energy intake and expenditure in Andrena ilerda and A. leaena (Hymenoptera: Andrenidae)" 4 : 41-47, 1989
22 Heinrich, B., "Energetics of pollination" 6 : 137-171, 1975
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26 Stiles, F. G., "Ecology, flowering phenology, and hummingbird pollination of some Costa Rican Heliconia" 56 : 285-301, 1975
27 Waddington, K. D., "Cost intake information used in foraging" 31 : 891-897, 1985
28 Schaffer, W. M., "Competition foraging energetics and cost of sociality in three species bees" 60 : 976-987, 1979
29 Colwell, R. K., "Competition and coexistence in a simple tropical community" 107 : 737-760, 1973
30 Heinrich, B., "Coevolution of Animals and Plants" Univ. Texas Press 141-158, 1975
31 Heinrich, B., "Bumblebee economics" Harvard University Press 1979
32 Sokal, R. R., "Biometry" W.H Freeman &Co. 1981
33 Abrol, D.P., "Bioenergetics in bee flowers interrelationships-an analysis of foraging behaviour" 7 : 39-66, 1992
34 Krebs, J.R., "Behavioural Ecology - An evolutionary Approach" Blackwell Scientific Publications 1983