Inverting the last condition of the query above, this is for blocks which are referenced by one or more other blocks:
#+BEGIN_QUERY
{:query [:find (pull ?b [*])
:in $ ?current
:where
[?p :block/name ?current]
[?b :block/page ?p]
[?other :block/refs ?b]
]
:inputs [:current-page]
}
#+END_QUERY