Columbia subject headings:
Esophagus--Cancer.
Smoking--South Africa--Transkei.
Tobacco--Physiological effect.
Xhosa (African people)--Alcohol use.
Harvard subject headings:
Esophagus--Cancer--South Africa--Transkei--Statistics.
Xhosa (African people)--Alcohol use
Xhosa (African people)--Diseases.
Xhosa (African people)--Tobacco use.
Princeton subject headings: