Latest version:

Guidelines for the optimal use of Digital Object Identifiers as permanent unique identifiers for germplasm samples - v.2 (http://www.fao.org/3/a-bt114e.pdf)

Also available in French, Spanish and Arabic

Outdated version:

Guidelines for the optimal use of Digital Object Identifiers as permanent unique identifiers for germplasm samples - v.1 (http://www.fao.org/3/a-bq549e.pdf)