Perhaps you should try some spelling variations:
sach thu » sach thue, sach thieu, sach tham
sach ty » sach y, sach tu, xach tay
nang ma » tang ma, sang ma, nang cao
qua cam » qua cham, qua cac, qua ca
xuc van » luc van, vuc van, xuc ban
duc van » duc va, duc tan, duc manh
vat cua » mat cua, bat cua, dat cua
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: tu ((sach ty) or (sach thu)) nang ma hoi. hieu qua cam ((xuc van) or (duc van)) sinh vat cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach ty) OR (sach thu)) nang ma hoi. hieu qua cam ((xuc van) OR (duc van)) sinh vat cua tre.
• Adding a wildcard symbol may retrieve word variants: tu ((sach ty) or (sach thu)) nang ma hoi. hieu qua cam ((xuc van) or (duc van)) sinh vat cua tre*.