Perhaps you should try some spelling variations:
hieu cac » hieu luc, hieu va, hieu van
danh dai » danh dau, danh di, danh sai
dua tren » dung tren
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
cac cau » cac mau, bac cau, ca cau
truc va » thuc va, thuc vat, trung va
va danh » va dinh, va dan, va hanh
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 hoi. hieu cac cau truc va danh dai ((dua tren) or (cuu tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang xa hoi. hieu cac cau truc va danh dai ((dua tren) OR (cuu tre)).
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang xa hoi. hieu cac cau truc va danh dai ((dua tren) or (cuu tre))*.