Citation Hunt

The Wikipedia snippet below is not backed by a reliable source. Can you find one?

Click I got this! to go to Wikipedia and fix the snippet, or Next! to see another one. Good luck!

In page M26 Pershing:

"

The M26 was the culmination of a series of medium tank prototypes that began with the T20 in 1942 and was a significant design departure from the previous line of U.S. Army tanks that had ended with the M4 Sherman. Several design features were tested in the prototypes. Some of these were experimental dead-ends, but many become permanent characteristics of subsequent U.S. Army tanks.[1] The prototype series began as a medium tank upgrade of the M4 Sherman and ended as the U.S. Army's first operational "heavy" tank.