Perhaps you should try some spelling variations:
cau tren » cu tren, dau tren, ca tren
su sach » so sach, vu sach
sach ky » sac ky, sach y, sach ty
nang ma » tang ma, sang ma, nang cao
hieu va » lieu va, hieu qua
va chat » van chat, va phat, cao chat
danh ve » dinh ve, hanh ve, anh ve
luc va » tuc va, loc va
ve cau » ke cau, va cau, ve cac

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sach ky ((nang x) or (nang ma)) hoi. hieu va chat ((luc va) or (duc va)) danh ve cau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky ((nang x) OR (nang ma)) hoi. hieu va chat ((luc va) OR (duc va)) danh ve cau tren.
• Adding a wildcard symbol may retrieve word variants: su sach ky ((nang x) or (nang ma)) hoi. hieu va chat ((luc va) or (duc va)) danh ve cau tren*.