Semantically equivalent PubMed and Ovid-MEDLINE queries: different retrieval results because of database subset inclusion.
Martin
M
Boeker
Werner
W
Vach
Edith
E
Motschall
D018501:Antirheumatic Agents / Q000627:therapeutic use*; D001172:Arthritis, Rheumatoid / Q000188:drug therapy*; D006801:Humans; D008727:Methotrexate / Q000627:therapeutic use*; D039781:PubMed / Q000592:standards*; D016032:Randomized Controlled Trials as Topic / Q000706:statistics & numerical data*
D018501:Antirheumatic Agents; D008727:Methotrexate