The person whose work you borrow deserves to remain visible in the result.

Borrowed work has a way of losing its origin. A phrase, a method, a design or a fix gets used, adapted and passed along, and by the third telling nobody remembers whose it was, including you. Attribution is not a formality, since being visible in a result is often the only payment somebody receives. The credit costs you a sentence and matters to them for years.

Name the source when you present the work, in the room and in the document. If you are unsure whose idea it was, ask rather than quietly assuming it was yours.