Issued Patents 1989
Showing 1–1 of 1 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4837481 | Cerium and terbium activated luminescent material and mercury vapor discharge lamp containing the same | Johannus G. Verlijsdonk, Emiel P. J. de Meester, Willebrordus H. M. M. Van de Spijker, Johannes G. Verriet | 1989-06-06 |