Title On a relation between the perfect Roman domination and perfect domination numbers of a tree Type of Research Article Keywords On a relation between the perfect Roman domination and perfect domination numbers of a tree Abstract On a relation between the perfect Roman domination and perfect domination numbers of a tree Researchers Zehui Shao (First Researcher)، saeed kosari (Second Researcher)، Mustapha Chellali (Third Researcher)، Seyed Mahmoud Sheikholeslami Kavkani (Fourth Researcher)، (Fifth Researcher)