On Some Questions About Selective Separability
CH implies that selective separability is not preserved by finite powers (solving [3, Problems 3.7 and 3.9]). In ZFC, selective separability does not imply H-separability (solving [4, Problem 34]).
Babinkostova, Liljana. (2009). "On Some Questions About Selective Separability". Mathematical Logic Quarterly, 55(5), 539-541. https://doi.org/10.1002/malq.200810010