This trend is visible especially in the most recent monographs on the Heroides.
For a list of more recent monographs and pointers to the extensive literature see To Learn More below.
The most recent and authoritative monograph dealing with this genus is Wiktor (2000).
This is the most recent comprehensive monograph.
A more recent monograph by Clarke restores N. longifolia to specific rank.
Perhaps most notably, Ernest Sosa (2007) has devoted a chapter of a recent monograph to the topic.
Among the most recent monographs (in English) are:
The following description is adapted from the most recent monograph on Lamiaceae.
In a recent monograph, he declares that, unlike most architects, he regards all his designs, built or unbuilt, as projects.
He also does not repeat careless errors from the most recent scholarly monograph on the artist.
