Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
sach thi » sach thu, sach tai, sach thieu
thi hanh » thi thanh
cac thuc » cach thuc, cac thu, can thuc
hanh lai » hanh lam, thanh lap, thanh loi
hanh tai » thanh tai, hang tai, han tai
hanh ma » hanh mau, hanh may, hanh va
hieu va » lieu va, hieu qua
thuc va » thuc vat, thuc dan, thuc day
cua tre » cua te, cuu tre, cua triet
ma hoi » mai hoi, xa hoi, ma hoa

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

• Performing a fuzzy search may retrieve terms with similar spellings: toc sach thi hanh ma hoi. hieu va cac thuc va ((hanh lai) OR (hanh tai)) cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach thi hanh ma hoi. hieu va cac thuc va ((hanh lai) OR (hanh tai)) cua tre".
• Adding a wildcard symbol may retrieve word variants: toc sach thi hanh ma hoi. hieu va cac thuc va ((hanh lai) OR (hanh tai)) cua tre*.