Columbia subject headings:
Sugar factories--Puerto Rico--Gurabo.
Sugar factories--Puerto Rico--Turabo River Valley--History.
Sugarcane industry--Puerto Rico--Gurabo.
Sugarcane industry--Puerto Rico--Turabo River Valley--History.
Harvard subject headings:
Sugar factories--Puerto Rico--Gurabo.
Sugar factories--Puerto Rico--Turabo River Valley--History.
Sugarcane industry--Puerto Rico--Gurabo.
Sugarcane industry--Puerto Rico--Turabo River Valley--History.
Princeton subject headings:
Sugar factories--Puerto Rico--Gurabo.
Sugar factories--Puerto Rico--Turabo Valley--History.
Sugarcane industry--Puerto Rico--Gurabo.
Sugarcane industry--Puerto Rico--Turabo Valley--History.