| Article ID: | iaor20002338 |
| Country: | Germany |
| Volume: | 86 |
| Issue: | 1 |
| Start Page Number: | 187 |
| End Page Number: | 197 |
| Publication Date: | Jan 1999 |
| Journal: | Mathematical Programming |
| Authors: | Yuan Y., Chen X. |
We extend an interesting theorem of Yuan for two quadratic forms to three matrices. Let