Perhaps you should try some spelling variations:
hoc sach » hoc sinh, hoc cac, hoc anh
cau treo » cau theo, cau tren, cau triet
hieu va » lieu va, hieu qua
nang xa » nang x, lang xa, nang ma
thuc va » thuc dan, thuc day
sach ky » sac ky, sach y, sach ty
dan tai » van tai, dan thi, ban tai
han tai » hang tai, nhan tai, van tai
va nam » van nam, ha nam, va nay

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 nang xa hoi. hieu va nam ((thuc va) or (thuc vat)) ((dan tai) OR (han tai)) cau treo~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc sach ky nang xa hoi. hieu va nam ((thuc va) OR (thuc vat)) ((dan tai) OR (han tai)) cau treo.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc sach ky nang xa hoi. hieu va nam ((thuc va) or (thuc vat)) ((dan tai) OR (han tai)) cau treo".
• Adding a wildcard symbol may retrieve word variants: hoc sach ky nang xa hoi. hieu va nam ((thuc va) or (thuc vat)) ((dan tai) OR (han tai)) cau treo*.