There + verb + multiple singular subjects

[Hela]

Hello,

I read that when the expletive "there" is followed by 2 singular subjects, the verb should be singular. The reason for it is that it avoids the repetition of "there is a dictionary and there is a notebook on the desk." Is this grammatically correct or is it "informal English"?

For example, would you say:
There is a dictionary and a notebook on the teacher's desk.
or
There are a dictionary and a notebook... ?

Thank you for your help.

[Alan]

Both possible, but the second is less natural/conversational.