Perhaps you should try some spelling variations:
su sach » so sach, vu sach
mai hoi » mai khoi, dai hoi, lai hoi
cac tuc » cac toc, cac tu, cac tac
van cac » van hac, van cau, van bac
sach ty » sach y, sach tu, sach thu
thi van » thi lan, thi hanh, thi nang
ty nang » ky nang, ty xang, ty hang
cuu tre » cua tre, cau tren, cau treo
ma hoi » xa hoi, ma hoa, me hoi
tuc va » thuc va, truc va, tuc xa
dan vi » doan vi, dan va, gan vi

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sach ty nang ((ma hoi) OR (mai hoi)). thi van cac tuc va ((dan vi) or (don vi)) cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ty nang ((ma hoi) OR (mai hoi)). thi van cac tuc va ((dan vi) OR (don vi)) cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ty nang ((ma hoi) OR (mai hoi)). thi van cac tuc va ((dan vi) or (don vi)) cuu tre".
• Adding a wildcard symbol may retrieve word variants: su sach ty nang ((ma hoi) OR (mai hoi)). thi van cac tuc va ((dan vi) or (don vi)) cuu tre*.