(tubular neighbourhood theorem)
Every embedding does admit a tubular neighbourhood.
For instance (DaSilva, theorem 3.1).
Moreover, tubular neighbourhoods are unique up to homotopy in a suitable sense:
This appears as (Godin, prop. 31).
Basics on tubular neighbourhoods are for instance in section 3 of
The homotopical uniqueness of tubular neighbourhoods is discussed in
For an analogue in homotopical algebraic geometry see