Guilbert and Betelle are represented in the 14th Edition of The Encyclopædia Britannica (1929, vol. 20; SARS to SORC), under the heading School Architecture. It’s a one-paragraph blurb describing Columbia High School, accompanied by the first floor plan (which incorrectly places CHS in South Orange; the building is in Maplewood):

“The Columbia high school, South Orange and Maplewood N.J., designed by Guilbert and Betelle, is a building with a capacity of 1,600 pupils. There are standard class-rooms supplemented by rooms for special subjects. The auditorium seats 1,300 persons and on the large stage is a pipe organ. Full size gymnasiums are provided for both boys and girls, and between the gymnasiums is a swimming pool with spectator’s gallery.”

This entry is among a number of other ones describing progressive American school architecture. While certainly an honorable mention for CHS, the editorially neutral wording belies how some histories have exaggerated this item.