Perhaps you should try some spelling variations:
thuat sach » thuat lanh, thuat san
phan duc » pham duc, phan tu, phan dau
su triet » su viet, su tien, ve triet
nang ma » tang ma, sang ma, nang cao
hieu ve » hieu van
hieu va » lieu va, hieu qua
sach ty » sach y, sach tu, sach thu
ty nang » ky nang, ty xang, ty hang
va danh » va dinh, va dan, va hanh
va tinh » may tinh
vi su » va su, ve su, ki su

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

• Performing a fuzzy search may retrieve terms with similar spellings: thuat sach ty nang ma hoa. ((hieu ve) OR (hieu va)) phan duc ((va danh) or (va tinh)) vi su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuat sach ty nang ma hoa. ((hieu ve) OR (hieu va)) phan duc ((va danh) OR (va tinh)) vi su triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thuat sach ty nang ma hoa. ((hieu ve) OR (hieu va)) phan duc ((va danh) or (va tinh)) vi su triet".
• Adding a wildcard symbol may retrieve word variants: thuat sach ty nang ma hoa. ((hieu ve) OR (hieu va)) phan duc ((va danh) or (va tinh)) vi su triet*.