Perhaps you should try some spelling variations:
sach doi » sach hoi, sach moi, sach dao
nang ma » tang ma, sang ma, nang cao
cac luc » cau luc, coc luc, cac nuoc
hieu ve » hieu va, hieu van
sach lo » sach dao, sach hoi, sach moi
cua tre » cua te, cuu tre, cua triet
lang xa » lang ha, dang xay, lang van
ve cac » va cac, vien cac
luc va » duc va, tuc va, loc va
va dan » ca dan, va dao, va dau
dan vi » doan vi, don vi, dan va
vi cua » vai cua, di cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: vu ((sach lo) or (sach doi)) ((lang xa) or (nang ma)) hoi. hieu ve cac luc va dan vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu ((sach lo) OR (sach doi)) ((lang xa) OR (nang ma)) hoi. hieu ve cac luc va dan vi cua tre.
• Adding a wildcard symbol may retrieve word variants: vu ((sach lo) or (sach doi)) ((lang xa) or (nang ma)) hoi. hieu ve cac luc va dan vi cua tre*.