السر الغريغوري
Subtitle: Gregorian secret
By: Wasīm Fāyiz. 
Publisher: Wasīm Fāyiz
Published: 2018
Place of publication: Cairo
Language: ara
Number of pages: 48
Subjects: Gregorian chants; History and criticism
Other titles: al-Sirr al-Ghirīghūrī; Gregorian secret
Notes: Includes bibliographical references (page 48).