The official "list" of SKUs is here: https://docs.microsoft.com/en-us/azure/active-directory/users-groups-roles/licensing-service-plan-reference

Sadly, it's still incomplete.

Hi,

A1 and A3 is the following.

"STANDARDPACK_STUDENT" = "Office 365 (Plan A1) for Students"
"ENTERPRISEPACK_STUDENT" = "Office 365 (Plan A3) for Students"

Did not find the SKU for A5, but the A4 was this (could be the same for A5)
"ENTERPRISEWITHSCAL_STUDENT" = "Office 365 (Plan A4) for Students"

Check this list by Robert Crane 

https://github.com/directorcia/Office365/blob/master/o365-skus.ps1

If you have the license in your tenant you can run the following powershell cmd to check

Get-AzureADSubscribedSku | Select -Property Sku* | fl