The phrase "author asserts" is correct and usable in written English.
It can be used when discussing the claims or statements made by an author in a text or scholarly work.
Example: "In her article, the author asserts that climate change is the most pressing issue of our time."
Alternatives: "the author claims" or "the author states".
The author asserts that the use of isolation and restraints is widespread.
The author asserts that "naught upon Earth is wrought in thy despite, O God" and that in Zeus all things are harmonized.
If she can't do it, she won't read on; if she does do it, she is in the mood to accept everything the author asserts as true.
Your April 17 obituary of Edward Gorey, the artist and author, asserts that he was "one of the most aptly named figures in American art and literature".
Now, 250 years on, the gripes have a familiar ring, especially when the author asserts that "In their employments they … stand in the way of our own people".
The author asserts that the answers developed by Egyptian intellectuals and state modernisers to the challenge modernity poses revolved around the problem of Islam.
The author asserted teachers' beliefs have been found to play a significant role in the implementation of inquiry-based lessons.
In a previous review, the same author asserted that the risk of childhood cancer was negligible at doses of less than 50 mGy [37].
An analysis in Kirkus Reviews, noting the choice of title by the author, asserted that Pressman: "makes no pretense to objectivity here".
Could it be, the author asserted, we are spending so much time questing to be social online that we're losing ourselves offline?
The author asserted that CTE was a progressive and non-reversible condition that progressed steadily even after the exposure to head trauma had ceased [ 22].
