Perhaps you should try some spelling variations:
viet cac » viet ca, viet bac, viet cau
danh vai » danh sai, danh va, doanh van
van danh » van doanh, van anh, van hanh
vien cac » vien bach, vien dai, vien da
vai cuu » vai cua
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
lang xa » lang ha, dang xay, lang van
nang xa » nang x, nang ma, mang xa
cuu tre » cua tre, cau tren, cau treo

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach ky ((nang xa) or (lang xa)) hoi. sieu ((viet cac) OR (vien cac)) vo van danh vai cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky ((nang xa) OR (lang xa)) hoi. sieu ((viet cac) OR (vien cac)) vo van danh vai cuu tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky ((nang xa) or (lang xa)) hoi. sieu ((viet cac) OR (vien cac)) vo van danh vai cuu tre*".