| A fleet of ice crushers and exploring planes were sent to locate the protium mines of the Arctic. |
| Once the passage is revealed and the protium traffic stopped, the food stores cannot last longer. |
| I was prevented from doing this immediately by difficulties in the protium Works. |
| Unless you chemists can solve the protium problem, Germany must cut her population swiftly, if we do not starve out altogether. |
| We had supposed you would have been told when you were assigned to the protium research. |
| These differences are best illustrated by the three isotopes of hydrogen: protium, deuterium and tritium. |
