Perhaps you should try some spelling variations:
thuoc sach » nuoc sach, thuat sach, thuoc sinh
hoc sach » hoc sinh, hoc cac, hoc anh
hanh va » hang va, hanh vi
va hanh » van hanh, va thanh, va danh
duoc va » nuoc va, duc va, duoc ma
hieu ve » hieu va, hieu van
hang ca » hang va, nang cao, hang tai
ty hang » ly hang, ty xang, thi hang
cua cau » cua cac, cua chu, cua cay
ca hoi » cau hoi, cua hoi, xa hoi
ve tao » ve bao, de tao, ve tac
cua cu » cua chu, cua su, cua co

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((thuoc sach) or (hoc sach)) ty hang ca hoi. hieu ve tao duoc va hanh va ((cua cu) OR (cua cau))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((thuoc sach) OR (hoc sach)) ty hang ca hoi. hieu ve tao duoc va hanh va ((cua cu) OR (cua cau)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((thuoc sach) or (hoc sach)) ty hang ca hoi. hieu ve tao duoc va hanh va ((cua cu) OR (cua cau))".
• Adding a wildcard symbol may retrieve word variants: ((thuoc sach) or (hoc sach)) ty hang ca hoi. hieu ve tao duoc va hanh va ((cua cu) OR (cua cau))*.