Perhaps you should try some spelling variations:
"cronicas americano en anestesiologia ;" » "cronicas americanas en anestesiologia ;", "cronica mexicana en anestesiologia ;", "tropico americano en anestesiologia ;", "cronicas americano de anestesiologia ;", "cronicas americana en anestesiologia ;"
"prensa mexicana en anestesiologia ;" » "prensa mexicana de anestesiologia ;", "poesia mexicana en anestesiologia ;", "prensa mexico en anestesiologia ;", "revista mexicana en anestesiologia ;"

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

• If you are trying to use Boolean operators, they must be ALL CAPS: (("cronicas americano en anestesiologia ;") OR ("prensa mexicana en anestesiologia ;"))~.
• Removing quotes may allow a broader search: (( cronicas americano en anestesiologia ; ) or ( prensa mexicana en anestesiologia ; ))~.
• Adding a wildcard symbol may retrieve word variants: (("cronicas americano en anestesiologia ;") or ("prensa mexicana en anestesiologia ;"))*.