<a href="https://doi.org/10.53656/math2021-1-8-kon" target="_blank" rel="noopener noreferrer">https://doi.org/10.53656/math2021-1-8-kon</a> [emember_protected for='16-8-24' format_protected_msg='1' custom_msg='<a href="/member-login/">Влезте в системата, за да прочетете пълната статия</a>']<a style="color: #ff0000;" href="https://azbuki.bg/wp-content/uploads/2021/02/Konkursni-zadachi.pdf" target="_blank" rel="noopener noreferrer">Отвори пълния текст</a>[/emember_protected] <h3></h3>