MENYALO, A.; RAPIN, V. Oscillator tracking filter with nonlinear feedback. Radiotekhnika, [S. l.], v. 3, n. 194, p. 119–126, 2018. DOI: 10.30837/rt.2018.3.194.16. Disponível em: http://rt.nure.ua/article/view/175347. Acesso em: 14 apr. 2025.