Hue, T.
(2002).
 On the radical characteristic of regularities.
<em>VNU Journal Of Science: Mathematics - Physics, 18</em>(1).
Retrieved from <a href="https://js.vnu.edu.vn/MaP/article/view/3227" target="_new">https://js.vnu.edu.vn/MaP/article/view/3227</a>