Abstract In Kiukas, Lahti, and Ylinen (2006, Journal of Mathematical Physics 47, 072104), the authors asked following general question. When is a positive operator measure projection valued? A version this question formulated in terms moments was posed Pietrzycki Stochel (2021, Functional Analysis 280, 109001). Let T be self-adjoint operator, let F Borel semispectral on real line with compact s...