Submillimeter spectroscopy of H<sub>2sub>C<sup>17sup>O and a revisit of the rotational spectra of H<sub>2sub>C<sup>18sup>O and H<sub>2sub>C<sup>16sup>O
H2C17O submillimeter spectrum studied up to 1.5 THz in natural isotopic composition. Additional data obtained for H2C18O and H2C16O. Combination with previous data yielded improved spectroscopic parameters.