Singly and doubly deuterated formaldehyde in massive star-forming regionsS. Zahorecz, I. Jimenez-Serra, L. Testi, K. Immer, F. Fontani, P. Caselli, K. Wang and T. OnishiA&A, 653 (2021) A45DOI: https://doi.org/10.1051/0004-6361/201937012