Here are a few links –
- https://www.cancer.net/cancer-types/leukemia-chronic-lymphocytic-cll
- https://www.mayoclinic.org/diseases-conditions/chronic-lymphocytic-leukemia/symptoms-causes/syc-20352428
- https://www.cancer.org/cancer/chronic-lymphocytic-leukemia/about.html
- https://www.webmd.com/cancer/lymphoma/chronic-lymphocytic-leukemia-rare#091e9c5e80fdaab9-1-3
- https://emedicine.medscape.com/article/199313-overview