Task: Question Generation
Input (English): #1 return documents 
#2 return budget types codes of  #1 
#3 return #1 where  #2 is  'GV 
#4 return #1 where  #2 is  'SF 
#5 return #1 of  both #3 and #4 
#6 return dates of  creation of #5
Output (English): Give the dates of creation for documents that have both budget type codes 'GV' and 'SF'.