Olonkins, S., J. Putrina, and V. Bobrovs. “Performance Comparison of Single-Pump FOPA and LRA in a 16-Channel DWDM Transmission System”. Elektronika Ir Elektrotechnika, vol. 25, no. 1, Feb. 2019, pp. 72-75, doi:10.5755/j01.eie.25.1.22740.