1. Childress, D. L.; Hayes, W. V. Dehydration catalyst for making ethylenimine. US4301036, 1981.
2. Liu, Z.W.; Huang, G-Q.; Lu, J.; Hou, Y.X.; Liu, Z.T.; Yang, J.M. Catalyst for intramolecular dehydration of monoethanolamine. ZL1 0547872.4, 2015.
3. Liu, Z.W.; Lu, J.; Huang, G-Q.; Liu, Z.T.; Yang, J.M.; Hou, Y.X. Acid activated montmorillonite supported cesium catalyst for producing azyridine from monoethanolamine. ZL1 0548532.3, 2015.
4. Liu, Z.W.; Hou, Y.X.; Lu, J.; Huang, G-Q.; Yang, J.M.; Liu, Z.T. Process for preparation of piperazine and its derivatives via gas-phase catalytic dehydration of monoethanolamine. ZL1 0548534.3, 2015.
5. Acid–base catalysis: on the example of ethylenimine production