1. 1934.Farrar (C. L.). — Bees must have pollen (Glean. Bee Cult.,62, 276–278).—Farrar (C.L.). 1936. Influence of pollen reserves on the surviving populations of over-wintered colonies (Amer. Bee J.,76, 452–454).—Farrar (C. L.) 1949. (in ≪The Hive and the Honey Bee≫, ch. XIV, Hamilton., Ill. Dadant.)
2. 1951.Jefferee (E. P.). — A photographic presentation of estimated numbers of honeybees (Apis mellifera L.) on combs in 14×8 1/2 inch frames (Bee World,32 [12], 89–91).—Jeffree (E. P.) 1955. Observations on the decline and growth of honeybee colonies (Journ. Econ. Ent. 48 [6], 723–726).
3. 1954.Mitchell (T. J.), Donald (E. M.), Kelso (J. R. M.). — An Examination of Scottish Heather Honey (Analyst,79, 435–442).
4. 1925.Nolan (W. J.). — The brood-rearing cycle of the honeybee (U. S. Dept. Agr. Dept. Bull. n o 1349).
5. 1947.Wedmore (E. B.). — (In ≪The Ventilation of Bee-Hives≫, ch. X, Petts Wood, Kent. Bee Craft.)