Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
tu sach » thu sach, su sach, te sach
va tinh » may tinh
va hanh » van hanh, va thanh, va danh
van cau » van dau, van hau, van chat
ma hoi » mai hoi, xa hoi, ma hoa
y nang » ky nang, ly nang, may nang
v nang » va nang, vu nang, van nang
di cua » dai cua, doi cua, de 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 ((y nang) OR (v nang)) ma hoi. hieu van cau truc ((va hanh) or (va tinh)) di cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((y nang) OR (v nang)) ma hoi. hieu van cau truc ((va hanh) OR (va tinh)) di cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ((y nang) OR (v nang)) ma hoi. hieu van cau truc ((va hanh) or (va tinh)) di cua te".
• Adding a wildcard symbol may retrieve word variants: tu sach ((y nang) OR (v nang)) ma hoi. hieu van cau truc ((va hanh) or (va tinh)) di cua te*.