What major reason did the senate fail to ratify the treaty of versailles?

How should the student cite this source using mla citation format?

What was a immediate cause of the panic of 1837

After the success of the sputnik launch, the united states feared that they would never be able to launch their own satellite, the ussr had used technology developed by the united states, the soviets had superior nuclear capabilities, that any future us satellites would not be as successful.