11. "' The template makes a footnote reference stating "': Calculated using Wikimedia Foundation Inc .. 12. The previous reference states that clinically silent MS plaques were located in the periventricular areas. 13. However, another reference states that Sayana suggested ten derivations. 14. Other references state that the existence of the city refers to the period of the Almoravids. 15. In 2008, an authoritative reference stated that the gray wolf could be found across mainland China. 16. One reference states that four 18-inch ( 457 mm ) torpedo tubes were added in 1894. 17. Some references state the class carried fore-and-aft sails as built, other references state they were never carried. 18. The internal energy is customarily stated relative to a conventionally chosen standard reference state of the system. 19. Another reference states that Davies Dyke closed permanently in March 1848 under the Edinburgh and Glasgow Railway. 20. This reference states that a 20 % to 30 % increase in engine thermal efficiency is possible.
