Perhaps you should try some spelling variations:
hanh doi » thanh doi, hanh noi, hang doi
te sach » toc sach
doi cua » dai cua, hoi cua
va cham » va chat, va tham
hieu va » lieu va, hieu qua
sach ty » sach y, sach tu, sach thu
nang ma » tang ma, sang ma, nang cao
luc va » tuc va, loc va
cua te » cua tu

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

• Performing a fuzzy search may retrieve terms with similar spellings: te sach ty ((nang x) or (nang ma)) hoi. hieu va cham ((luc va) OR (duc va)) hanh doi cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ty ((nang x) OR (nang ma)) hoi. hieu va cham ((luc va) OR (duc va)) hanh doi cua te*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ty ((nang x) or (nang ma)) hoi. hieu va cham ((luc va) OR (duc va)) hanh doi cua te*".