This is an example of how to cite an ISO standard in BibTeX:
@techreport{ISOPDF,
author = {ISO},
Institution = {International Organization for Standardization},
address = {Geneva, Switzerland},
Title = {Document management---{P}ortable document format---{P}art~1: {PDF}~1.7},
number = {32000\char"2012 1:2008},
Type = {ISO},
Year = {2008}
}
Note:\char"2012
from number
field is figure dash (‒). The ISO standard above is ISO 32000‒1:2008.