Yano-Melo, A.M., Vicente, C. and Xavier-Filho, L. (1999) “Allelopathic effect of the Cladonia verticillaris lichen extracts and fumarprotocetraric acid on the early growth of germinating seeds and seedlings in Allium cepa L”., International Journal of Horticultural Science, 5(3-4), pp. 31–35. doi:10.31421/IJHS/5/3-4/39.