1. A. BOOTSMA, 1976 .Frost Risk Survey of Prince Edward Island. Prince Edward Island Department of Agriculture and Forestry, Charlottetown, Prince Edward Island, Canada.
2. W. Y. CHIEW, 1976 . A study of summer maximum and minimum air temperatures over rolling terrain at Invermay . Unpublished B.Sc (Hons) thesis , Department of Geography, University of Otago.
3. S. N. EDEY, 1975 . Probability of freezing temperatures in the Spring and Fall in the Atlantic Region .Canada Department of Agriculture, Information Division, Publication 1565.