The claim that ionic bonding and electrostatic forces maintain the crystalline structure of sodium chloride is a fundamental and well-established scientific fact of solid-state chemistry and everyday chemical observation, requiring no formal citation of the retrieved literature.
The retrieved papers cover various topics such as sodium-ion batteries, ionogels, and hydrogels, but none directly test or discuss the fundamental chemical bonding mechanism of sodium chloride crystals as their primary subject. Because the statement is a standard definition of ionic crystal lattices taught in basic chemistry, it falls under common knowledge.