| Http://: https://www.rarediseases.org/rare-disease-information/rare-diseases/byID/645/viewAbstract |
| Http://: http://en.wikipedia.org/wiki/Primary_lateral_sclerosis |
| Http://: https://www.rarediseases.org/rare-disease-information/rare-diseases/byID/645/viewAbstract |
| Http://: http://en.wikipedia.org/wiki/Primary_lateral_sclerosis |