Produndizar en el tema

[ROBINDESBOIS]

Do we say deepen into the topic or see more in detail this topic?

[Perikles]

Do we say deepen into the topic or see more in detail this topic?I would say "to treat the topic in more depth" or "to treat the topic in more detail"

[poli]

...or to use a more idiomatic phrase: to dig deeper into the subject matter.