Systemic lupus erythematosus in a multiethnic US cohort (LUMINA) – XXV. Smoking, older age, disease activity, lupus anticoagulant, and glucocorticoid dose as risk factors for the occurrence of venous thrombosis in lupus patients - Calvo-Alen, J; Toloza, SMA; Fernandez, M (Arthritis Rheum, 2005)