Today(4/16), linking from PubMed to ”clecleLinker” has been troubled.

The error message ”Please include a Journal, ISSN, DOI, or 
PMID. The PubMed lookup service is temporarily unavailable.
Please try again later” will appear.

It has caused by PubMed. NLM is doing maintenance now.

Sorry for inconvenience.

 ==> 2013.4.17 Maintenance by NLM was finished, and the trouble was solved.