Columbia subject headings:
Harvard subject headings:
Allium fistulosum--Cytogenetics.
Allium fistulosum--Hybridization.
Allium--Cytogenetics.
Shallot--Cytogenetics.
Shallot--Hybridization.
Princeton subject headings:
Allium fistulosum--Cytogenetics.
Allium--Cytogenetics.
Plant hybridization.
Shallot--Cytogenetics.