Table 1.

Sample text on the topic of “lung cancer” from the three corpora

PubMed articles	…Marijuana smoke contains many of the same constituents as tobacco smoke, but whether it has similar adverse effects on pulmonary function is unclear…The Coronary Artery Risk Development in Young Adults (CARDIA) study, a longitudinal study collecting repeated measurements of pulmonary function and smoking over 20 years…
Reuter News	… A few hits on the bong now and then don’t seem to have any detrimental effects on lung health, suggests a new study. Researchers found that multiple measures of lung function actually improved slightly as young people reported using more marijuana …
Eligibility Criteria	Ages Eligible for Study: 18 Years and older Genders Eligible for Study: Both Inclusion Criteria:  • Pathologically confirmed, by biopsy or cytology, non-small cell lung carcinoma diagnosed within 3 months prior to study enrollment.  • T1, N0, M0 or T2, N0, M0.  • … Exclusion Criteria:  • Evidence of distant metastasis (M1) and/or nodal involvement (N1, N2, N3).