<?xml version="1.0" encoding="UTF-8"?>
<article article-type="Research Article">
  <front>
    <journal-meta>
      <journal-id journal-id-type="publisher">journal-of-discrete-mathematical-sciences-and-cryptography</journal-id>
      <journal-title-group>
        <journal-title>Journal of Discrete Mathematical Sciences and Cryptography</journal-title>
      </journal-title-group>
      <issn publication-format="electronic">2169-0065</issn>
      <issn publication-format="print">0972-0529</issn>
      <publisher>
        <publisher-name>Taru Publications</publisher-name>
      </publisher>
    </journal-meta>
    <article-meta>
      <article-id pub-id-type="doi">10.1080/09720529.2021.1930652</article-id>
      <title-group>
        <article-title>L(1, d)-labeling number of direct product of two cycles</article-title>
      </title-group>
      <contrib-group>
        <contrib contrib-type="author" corresp="yes">
          <name>
            <surname>Wu</surname>
            <given-names>Qiong</given-names>
          </name>
          <aff>Department of Computational Science, Tianjin University of Technology and Education, Tianjin, 300222, China</aff>
        </contrib>
        <contrib contrib-type="author">
          <name>
            <surname>Shiu</surname>
            <given-names>Wai Chee</given-names>
          </name>
          <aff>Department of Mathematics, The Chinese University of Hong Kong, Shatin, Hong Kong</aff>
          <aff>College of Global Talents, Beijing Institute of Technology, Zhuhai, China</aff>
        </contrib>
      </contrib-group>
      <volume>26</volume>
      <issue>8</issue>
      <fpage>2097</fpage>
      <lpage>2125</lpage>
      <pub-date date-type="pub">
        <day>24</day>
        <month>05</month>
        <year>2022</year>
      </pub-date>
      <abstract>
        <p>For positive number d, an L(1, d) -labeling f of G is an assignment of numbers to vertices of G such that |f(u) - f(v)| ≥ 1 if d(u, v) = 1, and |f(u) - f(v)| ≥ d if d(u, v) = 2. Then the span of f is the difference between the maximum and the minimum numbers assigned by f. The L(1, d) -labeling number of G, denoted by λ1,d (G), is the minimum span over all L(1, d) -labelings of G. In this paper, the authors give the L(1, d) -labeling numbers of the direct product of two cycles Cm and Cn for d ≥ 2 for some values of m and n. Some cases for 1 ≤ d </p>
      </abstract>
      <kwd-group>
        <kwd>Ld-labeling number</kwd>
        <kwd>Code assignment</kwd>
        <kwd>Direct product</kwd>
      </kwd-group>
      <custom-meta-group>
        <custom-meta>
          <meta-name>access</meta-name>
          <meta-value>open</meta-value>
        </custom-meta>
        <custom-meta>
          <meta-name>retracted</meta-name>
          <meta-value>no</meta-value>
        </custom-meta>
      </custom-meta-group>
    </article-meta>
  </front>
</article>
