Variability of angina. Some implications for epidemiology.
D000328:Adult; D000787:Angina Pectoris / Q000453:epidemiology*; D004562:Electrocardiography; D004812:Epidemiologic Methods; D006801:Humans; D008131:London; D008297:Male; D008875:Middle Aged; D009787:Occupational Medicine; D011795:Surveys and Questionnaires; D014505:Urban Population