実際のデータを見ると、世の中、いかに困難かがわかる

!Series_geo_accession = GSE11389
...
!Series_summary = This SuperSeries is composed of the following subset Series:
!Series_summary = GSE11335: Chip-chip from MEF cells with H3ac, H4ac, H4K20me1,
!Series_summary = GSE11337: RNA-chip from MEF cells
!Series_summary = GSE12721: Chip-seq from MEF cells H3K27me3
!Series_summary = Keywords: SuperSeries

おおおぅっ。