It is most usually found in the fields of history and philosophy though has on frequent occasion appeared outside these areas. (studentsassignmenthelp.com)
Regular, frequent time for students to write means regular, frequent occasions for us to teach students how to write. (heinemann.com)
And yet, on more frequent occasions of recitation than I'd like, I must admit to lacking the fervor that can overcome me when I remember I am speaking holy words. (firstthings.com)