If the publication does not have a publication year or date, the time n.d. (no date) shall be entered in the text reference.
(Seinäjoki University of Applied Sciences, n.d.)
According to Virtanen (n.d., p. 45)
(City of Seinäjoki, n.d., 2017, 2020)
- Arrange works by the same authors by year of publication. Place citations, with no date first, followed by works with dates in chronological order.