Perhaps you should try some spelling variations:
"cronica mexicana en medicina interna ;" » "botanica mexicana en medicina interna ;", "prensa mexicana en medicina interna ;", "cronica mexicana de medicina interna ;", "cronica mexicana la medicina interna ;"
"cartas americana de medicina interna ;" » "cartas americanas de medicina interna ;", "arts american de medicina interna ;", "carta africana de medicina interna ;", "cartas america de medicina interna ;", "cartas america del medicina interna ;"

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: (("cronica mexicana en medicina interna ;") OR ("cartas americana de medicina interna ;"))~.
• Removing quotes may allow a broader search: (( cronica mexicana en medicina interna ; ) or ( cartas americana de medicina interna ; ))~.
• Adding a wildcard symbol may retrieve word variants: (("cronica mexicana en medicina interna ;") or ("cartas americana de medicina interna ;"))*.