J:61711 Ulven SM, et al., Identification of endogenous retinoids, enzymes, binding proteins, and receptors during early postimplantation development in mouse: important role of retinal dehydrogenase type 2 in synthesis of all-trans-retinoic acid. Dev Biol. 2000 Apr 15;220(2):379-91

J:72547 Ulven SM, et al., Quantitative axial profiles of retinoic acid in the embryonic mouse spinal cord: 9-cis retinoic acid only detected after all-trans-retinoic acid levels are super-elevated experimentally. Dev Dyn. 2001 Nov;222(3):341-53