Perhaps you should try some spelling variations:
hieu vien » hieu hien, hieu viec, thieu nien
vien cac » vien bach, vien dai, vien da
sach ky » sac ky, sach y, sach ty
su sach » so sach, vu sach
nang xa » nang x, lang xa, mang xa
nang ma » tang ma, sang ma, nang cao
cuu tre » cua tre, cau tren, cau treo
xac va » tac va, ac va, bac va
tuc va » thuc va, truc va, tuc xa
vi cuu » vi luu, vinh cuu

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sach ky ((nang xa) or (nang ma)) hoi. hieu vien cac ((xac va) or (tuc va)) hanh vi cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky ((nang xa) OR (nang ma)) hoi. hieu vien cac ((xac va) OR (tuc va)) hanh vi cuu tre.
• Adding a wildcard symbol may retrieve word variants: su sach ky ((nang xa) or (nang ma)) hoi. hieu vien cac ((xac va) or (tuc va)) hanh vi cuu tre*.