character, data source, by default Pubmed/MedLine index will
be searched.
The following three letter codes represent the sources
Europe PubMed Central supports:
agr
Agricola is a bibliographic database of citations to the
agricultural literature created by the US National Agricultural Library
and its co-operators.
cba
Chinese Biological Abstracts
ctx
CiteXplore
eth
EthOs Theses, i.e. PhD theses (British Library)
hir
NHS Evidence
med
PubMed/Medline NLM
nbk
Europe PMC Book metadata
pat
Biological Patents
pmc
PubMed Central
limit
integer, number of results. By default, this function
returns 100 records.
verbose
logical, print some information on what is going on.