When referencing multiple works from the same author with a combination of no date, date and in press, the following order should be used:
date (in chronological order)
Brown & Jones (n.d., 2016, 2018, in press).
(APA manual, 2020, p. 263).
In press means that the work has been accepted for publication but has not yet been published.
The advice of the Nursing Council of New Zealand is :
Although in book form, and shelved with the books, MIMS New Ethicals should be treated as a serial because it comes out several times each year.
Then in your reference list
Somatropin. (2020). MIMS New Ethicals, January-June (32), 255