Perhaps you should try some spelling variations:
tham thuc » nham thuc, pham thuc, tam thuc
hoc sach » hoc sinh, hoc cac, hoc anh
nang mai » nang ma, nang tai, lang mai
lieu van » lieu va, hieu van, sieu van
van tham » van thanh, van tuan, van chat
danh dai » danh dau, danh di, vanh dai
danh sai » dung sai, danh bat, danh dau
mai hoi » mai khoi, dai hoi, lai hoi
cua tre » cua te, cuu tre, cua triet
sach v » sach va, sach y, sach 2
v nang » va nang, vu nang, van nang

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 v nang mai hoi. lieu van tham thuc vat ((danh dai) or (danh sai)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc sach v nang mai hoi. lieu van tham thuc vat ((danh dai) OR (danh sai)) cua tre.
• Adding a wildcard symbol may retrieve word variants: hoc sach v nang mai hoi. lieu van tham thuc vat ((danh dai) or (danh sai)) cua tre*.