Perhaps you should try some spelling variations:
giai thanh » gia thanh, gian thanh, giay thanh
cua triet » cua viet, su triet, va triet
thuc giai » thuoc giao, hoc giai, thuc thai
thanh vi » hanh vi, thanh va, thanh ve
lang van » dang van, tang van, hoang van
cac thuc » cach thuc, cac thu, can thuc
cuu tre » cua tre, cau tren, cau treo
bo sach » co sach, hoc sach
sach ty » sach y, sach tu, sach thu
nang ma » tang ma, sang ma, nang cao
hieu va » lieu va, hieu qua

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

• Performing a fuzzy search may retrieve terms with similar spellings: bo sach ty ((nang ma) or (lang van)) hoi. hieu va cac thuc giai thanh vi ((cuu tre) or (cua triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: bo sach ty ((nang ma) OR (lang van)) hoi. hieu va cac thuc giai thanh vi ((cuu tre) OR (cua triet)).
• Adding a wildcard symbol may retrieve word variants: bo sach ty ((nang ma) or (lang van)) hoi. hieu va cac thuc giai thanh vi ((cuu tre) or (cua triet))*.