1. Yu. N. Baulina, On the number of solutions of the equation (x1+⋯+xn)2 = ax1⋯xn in the finite field
$$
\mathbb{F}
$$
q for gcd(n —2, q—1) = 7 and for gcd(n —2, q—1) = 14 (Russian), Chebyshevskiῐ Sb. 1 (2001) 5–14.
2. Yu. N. Baulina, On the explicit formulas for the number of solutions of the equation (x1+⋯+xn)2 = ax1⋯xn in a finite field (Russian), Sibirsk. Mat. Zh. 44 (2003) 21–26; translation in Siberian Math. J. 44 (2003) 17–21.
3. Yu. N. Baulina, On the number of solutions of the equation (x1+⋯+xn)m = ax1⋯xn in a finite field (Russian), Diskret. Mat. 16 (2004) 41–48; translation in Discrete Math. Appl. 14 (2004) 501–508.
4. I. Baoulina, On a problem of Carlitz, Int. J. Number Theory
1 (2005) 293–307.
5. I. Baoulina, On a generalized problem of Carlitz, Chebyshevskiῐ Sb. 7 (2006) 129–139.