Perhaps you should try some spelling variations:
thu sach » thuat sach, thuoc sach, thu hoach
tay lang » tai lang, tay tang, tay quang
tu sach » su sach, te sach, tu cach
va hanh » van hanh, va thanh, va danh
cau luc » cau truc, cau phuc
hieu va » hieu qua
lang xa » lang ha, dang xay, lang van
luc va » duc va, tuc va, loc va
vi cua » vai cua, di cua
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: ((tu sach) or (thu sach)) tay lang xa hoi. ((hieu va) OR (lieu va)) cau luc va hanh vi cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (thu sach)) tay lang xa hoi. ((hieu va) OR (lieu va)) cau luc va hanh vi cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) or (thu sach)) tay lang xa hoi. ((hieu va) OR (lieu va)) cau luc va hanh vi cua te".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (thu sach)) tay lang xa hoi. ((hieu va) OR (lieu va)) cau luc va hanh vi cua te*.