Erasmus Darwin (1800). “Phytologia; Or, The Philosophy of Agriculture and Gardening: With the Theory of Draining Morasses, and with an Improved Construction of the Drill Plough”, p.556
Erasmus Darwin (1791). “The Botanic Garden; a Poem, in Two Parts. Part I. Containing The Economy of Vegetation. Part II. The Loves of the Plants. With Philosophical Notes”, p.9
Erasmus Darwin (1800). “Phytologia, or the philosophy of agriculture and gardening; with the theory of draining morasses and with an improved construction of the drill plough”, p.560