If you are looking for a deep dive (a "paper") on how these taxes work, these official handbooks are the best resources:
: Most corporation tax extensions and estimated tax payments must be filed electronically . Paper versions of these extensions (except Form CT-5.1) are generally no longer accepted for processing. nys-dtf-ct
: Used by corporations to report changes to unrelated business income or claim overpayments. Key Publications and Guidelines If you are looking for a deep dive