On the wikipedia page for Morse theory it states the following
A smooth real-valued function on a manifold M is a Morse function if it has no degenerate critical points. A basic result of Morse theory says that almost all functions are Morse functions. Technically, the Morse functions form an open, dense subset of all smooth functions M → R in the C2 topology. This is sometimes expressed as "a typical function is Morse" or "a generic function is Morse".
however no reference is given. After searching for a bit I cannot find this basic result in any papers on Morse Theory. Can anyone provide a reference for this statement?