Perhaps you should try some spelling variations:
thu sach » thuat sach, thuoc sach, thu hoach
nang mai » nang ma, nang tai, lang mai
tu sach » su sach, te sach, tu cach
mai hoi » mai khoi, dai hoi, lai hoi
hieu va » hieu qua
va danh » va dinh, va dan, va hanh
danh di » danh du, xanh di, danh dien
xuc va » duc va, tuc va, luc va
di hoa » dai hoa, doi hoa, do hoa

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)) ky nang mai hoi. ((hieu va) OR (lieu va)) cam xuc va danh di hoa viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (thu sach)) ky nang mai hoi. ((hieu va) OR (lieu va)) cam xuc va danh di hoa viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) or (thu sach)) ky nang mai hoi. ((hieu va) OR (lieu va)) cam xuc va danh di hoa viet".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (thu sach)) ky nang mai hoi. ((hieu va) OR (lieu va)) cam xuc va danh di hoa viet*.