DAMLAKHI, M. K. Riquier problem in a biharmonic space. Tamkang Journal of Mathematics, [S. l.], v. 34, n. 2, p. 99–106, 2003. DOI: 10.5556/j.tkjm.34.2003.256. Disponível em: https://journals.math.tku.edu.tw/index.php/TKJM/article/view/256. Acesso em: 22 jul. 2024.