Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
cau tren » cu tren, dau tren, ca tren
nang ma » tang ma, nang cao, mang may
sang ma » tang ma, sang tao, mang may
va cam » va cham, va cac, va cao
luc va » duc va, tuc va, loc va
vi cau » va cau, ve cau, di cau

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

• Performing a fuzzy search may retrieve terms with similar spellings: thu sach y ((nang ma) or (sang ma)) hoi. lieu va cam ((luc va) or (tuc xa)) hanh vi cau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach y ((nang ma) OR (sang ma)) hoi. lieu va cam ((luc va) OR (tuc xa)) hanh vi cau tren.
• Adding a wildcard symbol may retrieve word variants: thu sach y ((nang ma) or (sang ma)) hoi. lieu va cam ((luc va) or (tuc xa)) hanh vi cau tren*.