Title On a Conjecture About Signed Domination in the Cartesian Product of Two Directed Cycles Type of Research Article Keywords On a Conjecture About Signed Domination in the Cartesian Product of Two Directed Cycles Abstract On a Conjecture About Signed Domination in the Cartesian Product of Two Directed Cycles Researchers Zehui Shao (First Researcher)، Zhang Jiang (Second Researcher)، Mustapha Chellali (Third Researcher)، Seyed Mahmoud Sheikholeslami Kavkani (Fourth Researcher)، (Fifth Researcher)، Pu Wu (Not In First Six Researchers)، Bo Wang (Not In First Six Researchers)