Perhaps you should try some spelling variations:
"colloques, congres et conferences sur le xxe siecle" » "colloques, congres a conference sur le xxe siecle" (Expand Search), "colloques, congres et conferences sur la xxe siecle" (Expand Search), "colloque, congres et conferences sur le xxe siecle" (Expand Search), "colloques, congress et conferences sur le xxe siecle" (Expand Search), "colloques, kongress et conferences sur le xxe siecle" (Expand Search)
"colloques, congres _ conference sur le xvie siecles" » "colloques, congres _ conference _ le xvie siecles" (Expand Search), "colloques, congres _ conference where le xvie siecles" (Expand Search), "colloques, congres _ conference sur le xvie siecle" (Expand Search), "colloques, congres _ conference sur le xviiie siecle" (Expand Search), "colloques, congres _ conference sur la xvie siecles" (Expand Search), "colloque, congres _ conference sur le xvie siecles" (Expand Search), "colloques, congress _ conference sur le xvie siecles" (Expand Search), "colloques, kongress _ conference sur le xvie siecles" (Expand Search)

Try widening your search to All Fields.

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: (("colloques, congres et conferences sur le xxe siecle") or ("colloques, congres _ conference sur le xvie siecles"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("colloques, congres et conferences sur le xxe siecle") OR ("colloques, congres _ conference sur le xvie siecles")).
• Removing quotes may allow a broader search: (( colloques, congres et conferences sur le xxe siecle ) or ( colloques, congres _ conference sur le xvie siecles )).
• Adding a wildcard symbol may retrieve word variants: (("colloques, congres et conferences sur le xxe siecle") or ("colloques, congres _ conference sur le xvie siecles"))*.