Table 2 Electronic databases used for searching
Database | Searched field | No of hits | Date |
|---|---|---|---|
ISI Web of Science | topic | 3249 | 2013-02-26 |
Georef and Geobase | subject/title/abstract | 2249 | 2013-02-26 |
Scopus | title, abstract and keywords | 2842 | 2013-02-26 |
Agricola | keyword anywhere | 524 | 2013-02-26 |
ASFA | All fields (no full text) | 1933a) | 2013-02-27 |
Academic search | title/abstract/subject/keyword | 1131 | 2013-02-27 |
Biological Abstracts | keywords | 401 | 2013-02-27 |
Wiley Online Library | abstract or title or keywords | 174 | 2013-02-27 |
Directory of Open Access Journals | all fields | 84a) | 2013-03-05 |
ScienceDirect | abstract or title or keywords | 876 | 2013-07-02 |