E-Link UIDs one-to-one
Use History [use_history]
Query Key (In term, use %23 for #) [query_key]
First Record to retrieve [retstart]:
http://eutils.ncbi.nlm.nih.gov/entrez/eutils/.fcgi?&retmax=20
Complexity [complexity]: get the whole blob [0] get the bioseq for gi of interest [1] get the minimal bioseq-set [2] get the minimal nuc=prot set [3] get the minimal pub-set [4]