Perhaps you should try some spelling variations:
thuat sach » thuat lanh, thuat san
hieu van » hieu va, thien van, hieu ve
dang hai » dang khai, hang hai, dung hai
van dang » van dong, van dung, van nang
luoc van » luoc can, luoc va, luc van
cac luoc » cac nuoc, cac cuoc, cac quoc
sach ty » sach y, sach tu, sach thu
nang ma » tang ma, sang ma, nang cao
nang xa » nang x, lang xa, mang xa
hai cua » thai cua, dai cua, hoi cua
cua tu » cua tuc, cua su, cua cu

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

• Performing a fuzzy search may retrieve terms with similar spellings: thuat sach ty ((nang xa) or (nang ma)) hoi. ((hieu van) or (lieu va)) cac luoc van dang hai cua tu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuat sach ty ((nang xa) OR (nang ma)) hoi. ((hieu van) OR (lieu va)) cac luoc van dang hai cua tu.
• Adding a wildcard symbol may retrieve word variants: thuat sach ty ((nang xa) or (nang ma)) hoi. ((hieu van) or (lieu va)) cac luoc van dang hai cua tu*.