Cannot call methods of Reference

I don't know how to formulate the question properly, sorry in advance.

I have a basic LIST class, and a REPORT class, report->get_includes() returns TYPE REF TO LIST

When i try to compile the following code, i get the error saying i can't call a method from a reference
DATA(Y) = NEW REPORT( 'FOO' )->GET_INCLUDES( ).
DATA(Z) = Y->GET( 1 ).

When i change the return type of get_includes to TYPE LIST, i get the error saying "Y is not a reference variable"

So the errors say that i cannot call from a reference variable, but also have to call from a reference variable.

I hope i properly expressed myself, if i did not, i am happy to clarify.

Thanks in advance for any help!