Perhaps you should try some spelling variations:
trinh den » trinh dien, trinh dan, trinh dung
hieu vien » hieu hien, hieu viec, thieu nien
vien cac » vien bach, vien dai, vien da
te sach » toc sach
den cuu » dinh cuu, dien cuc, dien cua
sach ky » sac ky, sach y, sach ty
cuu tre » cua tre, cau tren, cau treo
lang xa » lang ha, dang xay, lang van
nang xa » nang x, nang ma, mang xa
tu may » tu ma, tu cay, tu mai
ty may » ty xay, ly may

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

• Performing a fuzzy search may retrieve terms with similar spellings: te sach ky ((nang xa) or (lang xa)) hoi. hieu vien cac ((tu may) OR (ty may)) trinh den cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ky ((nang xa) OR (lang xa)) hoi. hieu vien cac ((tu may) OR (ty may)) trinh den cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ky ((nang xa) or (lang xa)) hoi. hieu vien cac ((tu may) OR (ty may)) trinh den cuu tre".
• Adding a wildcard symbol may retrieve word variants: te sach ky ((nang xa) or (lang xa)) hoi. hieu vien cac ((tu may) OR (ty may)) trinh den cuu tre*.