The fact that the entry is given under Hugo would show that there was something in the book about him, but not that it concerned his romances only. There is also the reverse process of giving simply the title of the essay, as

Hugo, Victor.

Stevenson, R. L. Victor Hugo’s romances. 1888

The disadvantage of this form is that it would be taken for a whole book instead of an essay, but this difficulty could be got over by inserting the explanatory word “essay,” as

Hugo, Victor.

Stevenson, R. L. Victor Hugo’s romances [essay.] 1888

There is also the cross-reference form, like

Hugo, Victor.

See also Stevenson, R. L. Men and books.

which is the least desirable because it is vague and also extravagant so far as space is concerned.