Nguyen, Thi Dung and Hoang, Van Thanh and Nguyen, Dinh Lam  (2019) Influences of growth durations on characteristics of NaYF4:(Yb,Tm) upconversion materials.  Influences of growth durations on characteristics of NaYF4:(Yb,Tm) upconversion materials, 35  (4).    ISSN 0866-8612