Seyrekoğlu, F., and H. Temiz. “Effect of Extraction Conditions on the Phenolic Content and DPPH Radical Scavenging Activity of Hypericum Perforatum L”. Turkish Journal of Agriculture - Food Science and Technology, vol. 8, no. 1, Jan. 2020, pp. 226-9, doi:10.24925/turjaf.v8i1.226-229.3013.