| Vintage woodworking machinery trade catalogs have proved invaluable in uncovering the history of some of these companies. |
| The military working dogs have been invaluable for deterring criminal activity in the newly independent country. |
| A lot of invaluable literature in the languages of the common folk has remained outside recognised literary boundaries. |
| The Folger's collections have proved invaluable to a project we have undertaken on Africanism in early modern England and English America. |
| We had become more Jewishly involved, and had found the timeless wisdom of Torah to be an invaluable guide in many difficult situations. |
| His hundreds of sketchbooks were invaluable aide-memoire, and he kept them well organized so he could quickly locate what he wanted. |
