Perhaps you should try some spelling variations:
sach thu » sach thue, sach thieu, sach tham
cau tren » cu tren, dau tren, ca tren
sach ty » sach y, sach tu, xach tay
nang ma » tang ma, sang ma, nang cao
hieu va » lieu va, hieu qua
ma hoi » mai hoi, xa hoi, ma hoa
va cam » va cham, va cac, va cao
xuc va » tuc va, luc va, xac va
vi cau » va cau, ve cau, di cau

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

• If you are trying to use Boolean operators, they must be ALL CAPS: te ((sach ty) OR (sach thu)) nang ma hoi. hieu va cam ((xuc va) OR (duc va)) hanh vi cau tren~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te ((sach ty) or (sach thu)) nang ma hoi. hieu va cam ((xuc va) OR (duc va)) hanh vi cau tren~".
• Adding a wildcard symbol may retrieve word variants: te ((sach ty) or (sach thu)) nang ma hoi. hieu va cam ((xuc va) OR (duc va)) hanh vi cau tren*.