“Harmonization of Regulatory Authority between the Indonesian National Police and the National Narcotics Agency in the Use of Undercover Buy Techniques in Narcotics Crime Investigations”, SINGOSARI: Jur. P3SI Wil. Jatim, vol. 3, no. 2, pp. 64–71, Jul. 2026, doi: 10.63440/singosari.v3i2.146.