Perhaps you should try some spelling variations:
hoc sach » hoc sinh, hoc cac, hoc anh
nam thuc » nam thuoc, am thuc, nam thu
cau treo » cau theo, cau tren, cau triet
ky lang » ky nang, ky tang, tay lang
ky dang » ky nang, ky danh
hieu ha » hieu hoa, hieu va, hieu ca
thuc va » thuc vat, thuc dan, thuc day
dau vai » dau va, dau hai, dau tai
vai cau » va cau, van cau, vai cac
va dau » va dao

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc sach ((ky lang) or (ky dang)) xa hoi. hieu ha nam thuc va dau vai cau treo~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc sach ((ky lang) OR (ky dang)) xa hoi. hieu ha nam thuc va dau vai cau treo.
• Adding a wildcard symbol may retrieve word variants: hoc sach ((ky lang) or (ky dang)) xa hoi. hieu ha nam thuc va dau vai cau treo*.