Perhaps you should try some spelling variations:
nang mai » nang ma, nang tai, lang mai
tu sach » thu sach, su sach, te sach
mai hoi » mai khoi, dai hoi, lai hoi
hieu va » hieu qua
cau duc » cao duc, cau luc, chu duc
va hanh » van hanh, va thanh, va danh
y nang » ky nang, ly nang, v nang
vi cuu » vinh cuu
vi luu » vi lua

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 y nang mai hoi. ((hieu va) or (lieu va)) cau duc va hanh ((vi cuu) OR (vi luu)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach y nang mai hoi. ((hieu va) OR (lieu va)) cau duc va hanh ((vi cuu) OR (vi luu)) tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach y nang mai hoi. ((hieu va) or (lieu va)) cau duc va hanh ((vi cuu) OR (vi luu)) tre".
• Adding a wildcard symbol may retrieve word variants: tu sach y nang mai hoi. ((hieu va) or (lieu va)) cau duc va hanh ((vi cuu) OR (vi luu)) tre*.