valerian

Hi, in the income statement I get 90k income but if I tally up my invoices in google sheets for 2018 (including unpaid) they add up only to 59k. Where did the extra 30k came from? I mean I wouldn't mind it if the money was there but it is not. This is very frustrating. It seems there are duplicate records for some invoices but I have no clue how to check it. Please help. THANKS