Ščemeļevs, A., and J. Poriņš. 2009. “BER Performance of a Lumped Single-Pump Fiber Optical Parametric Amplifier in a 10 Gbit/S 4-Channel S-Band DWDM System”. Elektronika Ir Elektrotechnika 93 (5):11-14. https://eejournal.ktu.lt/index.php/elt/article/view/10170.