Huong, Le Thi Thu, Tobias Haeger, and The-Long Phan. 2018. “Study of Impurity in Blue Spinel from the Luc Yen Mining Area, Yen Bai Province, Vietnam”.
Vietnam Journal of Earth Sciences
40 (1):47-55. https://doi.org/10.15625/0866-7187/40/1/10915.