Please read the following table in Markdown format and then answer the question according to the table. Table cells in one row are seperated by '|', and different rows are seperated by '
'.

Table:
| Cartridge | Bullet weight | Muzzle velocity | Muzzle energy | Source |
| --- | --- | --- | --- | --- |
| .375 Dakota | gr (g) | ft/s (m/s) | ft·lbf (J) | Dakota Arms |
| .375 H&H Magnum | gr (g) | ft/s (m/s) | ft·lbf (J) | Hornady |
| .375 Remington Ultra Magnum | gr (g) | ft/s (m/s) | ft·lbf (J) | Remington |
| .375 Ruger | gr (g) | ft/s (m/s) | ft·lbf (J) | Hornady |
| .375 Winchester | gr (g) | ft/s (m/s) | ft·lbf (J) | Winchester |
| .375 Weatherby Magnum | gr (g) | ft/s (m/s) | ft·lbf (J) | Weatherby |
| .376 Steyr | gr (g) | ft/s (m/s) | ft·lbf (J) | Hornady |
Question:
What is Source, when Cartridge is .375 remington ultra magnum?
Answer:
Remington