Rules on Evidence
Section 46. Learned treatises. - A published treatise, periodical or pamphlet on a subject of history, law, science, or art is admissible as tending to prove the truth of a matter stated therein if the court takes judicial notice, or a witness expert in the subject testifies, that the writer of the statement in the treatise, periodical or pamphlet is recognized in his profession or calling as expert in the subject. (40a)