proof of work
it is my unit ( comrade) ( id number: _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ ) in _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ department, engaged in _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ work has been _ _ _ _ _ _ _ _ _ _ _ years, hereby certify that.
name of institution: _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
day period: _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
( seal)