One way you can do this is by running a Sales by Customer Detail report, with the details below.
1) Go to Reports
2) Select 'Sales by Customer detail'
3) Enter a custom date range in the date fields
4) Select Customise > Filter > Check 'A/R Paid' > Select Paid on the drop-down > Run report
The above report gives you those invoices that are dated April-June AND which have subsequently been paid.
If you're looking for a report that gives you the invoices that were paid between April-June (i.e. payments received in those months & the related invoices no matter when they were raised) there is the Invoices and Received Payments Report.
It lists all payments received, under each payment the invoices cleared. Grouped by Customer.