Annual technical report of the National Plant Materials Center - National Plant Materials Center (U.S.) (Soil Conservation Service, U.S. Dept. of Agriculture, 1980)

Annual technical report of the National Plant Materials Center - National Plant Materials Center (U.S.) (Soil Conservation Service, U.S. Dept. of Agriculture, 1979)

Bulletin of miscellaneous information - Royal Botanic Gardens, Kew. (H.M. Stationery Office, 1906)

Bulletin of miscellaneous information - Royal Botanic Gardens, Kew. (H.M. Stationery Office, 1907)

Just's Botanischer Jahresbericht - Just, Johann Leopold, 1841 -1891 (Gebruder Borntraeger, 1897)

Lake Nyasa climatic region : floristic checklist - Gereau, Roy E., (Missouri Botanical Garden, 2012)

Lake Nyasa climatic region : floristic checklist - Gereau, Roy E., (Missouri Botanical Garden, 2012)

Memoirs of the New York Botanical Garden - New York Botanical Garden (The Garden, 1953)