context: His student and collaborator, Vladimir Steklov, recalled his first lecture in the following way: A handsome young man, almost of the age of the other students, came before the audience, where there was also the old Dean, professor Levakovsky, who was respected by all students.
source: This subject was already known to the students from the lectures of professor Delarue.
reference_original: Este ya era un tema conocido por los estudiantes, por las clases del profesor Delarue.
reference_flipped: Este ya era un tema conocido por los estudiantes, por las clases de la profesora Delarue.