Çağlayan, N., E. Uçar, and C. Ertekin. “The Effect of Various Wavelengths of LED Light on the Physiological and Morphological Parameters of Comfrey (Symphytum Officinale L.)”. Turkish Journal of Agriculture - Food Science and Technology, vol. 8, no. 4, Apr. 2020, pp. 965-70, doi:10.24925/turjaf.v8i4.965-970.3230.