[see also: mention, allude, touch, appeal, invoke, recourse
For more details we refer the reader to [4].
The interested reader is referred to [4] for further information. [Note the double r in referred.]
In the physical context already referred to, K is the density of......
This theorem will hereafter be referred to as the minimum principle.
We refer to these as homogeneous Sobolev spaces.
We shall also refer to a point as backward nonsingular, with the obvious analogous meaning.
In the following, all topological notions refer to the weak topology of Y.
To be precise, refer to the notation in Theorem 1 and define......