Readers should cite both the Bio-protocol preprint and the original research article where this protocol was used:

Nigussie, D and Nigussie, D(2022). Test for tannins (ferric chloride test). Bio-protocol Preprint. bio-protocol.org/prep1690.
Nigussie, D., Davey, G., Legesse, B. A., Fekadu, A. and Makonnen, E.(2021). Antibacterial activity of methanol extracts of the leaves of three medicinal plants against selected bacteria isolated from wounds of lymphoedema patients. BMC Complementary Medicine and Therapies 0(0). DOI: 10.1186/s12906-020-03183-0