Phung, B.
(2017).
 A black-box model of optical  amplifier chains in optical fibre telecommunications systems.
<em>VNU Journal Of Science: Mathematics - Physics, 19</em>(3).
Retrieved from <a href="https://js.vnu.edu.vn/MaP/article/view/4093" target="_new">https://js.vnu.edu.vn/MaP/article/view/4093</a>