According the Mayo Clinic:<ref>[https://www.mayoclinic.org/healthy-lifestyle/stress-management/in-depth/positive-thinking/art-20043950 Positive thinking: Stop negative self-talk to reduce stress]</ref> | According the Mayo Clinic:<ref>[https://www.mayoclinic.org/healthy-lifestyle/stress-management/in-depth/positive-thinking/art-20043950 Positive thinking: Stop negative self-talk to reduce stress]</ref> |