Perhaps you should try some spelling variations:
hoc sach » hoc sinh, hoc cac, hoc anh
hanh tai » thanh tai, hang tai, han tai
vat hanh » vat thanh, van hanh, va hanh
le quang » vu quang
tai duc » tai cuc, mai duc, tai du
thu vat » thuc vat, thu va, thuat vat
cac thu » cach thuc, cac thoi
duc tre » duoc tren, duc tien
hieu va » lieu va
ly hang » ly quang

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 ((ly hang) or (le quang)) xa hoi. ((hieu va) or (hieu qua)) cac thu vat hanh tai duc tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc sach ((ly hang) OR (le quang)) xa hoi. ((hieu va) OR (hieu qua)) cac thu vat hanh tai duc tre.
• Adding a wildcard symbol may retrieve word variants: hoc sach ((ly hang) or (le quang)) xa hoi. ((hieu va) or (hieu qua)) cac thu vat hanh tai duc tre*.