As described by Brockhaus and Efron Encyclopedic Dictionary, what is the unit of length for the smallest conversion to a standard unit?
select ?ent where { ?ent wdt:P31 wd:Q1978718 . ?ent wdt:P2442 ?obj . ?ent wdt:P1343 wd:Q602358} ORDER BY ASC(?obj)LIMIT 5 
unit of length: Q1978718 brockhaus and efron encyclopedic dictionary: Q602358