Laudere, A., et al. "Reaction of Oxalic Acid with Iron Hydroxide and Iron Oxide. I. X-ray Diffraction Study." Latvijas PSR Zinatnu akademijas vestis. Kimijas serija 1 (1969): 23-26.

Laudere, A., et al. "Reaction of Oxalic Acid with Iron Hydroxide and Iron Oxide. I. X-ray Diffraction Study." Latvijas PSR Zinatnu akademijas vestis. Kimijas serija 1 (1969): 23-26.