Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
va thanh » gia thanh, ban thanh, va tinh
thanh di » thanh doi, thanh de, thanh do
tu sach » thu sach, su sach, te sach
van cau » van dau, van hau, van chat
truc va » thuc va, thuc vat, trung va
ca viet » va viet, co viet, hoa viet
y nang » ky nang, ly nang, may nang
v nang » va nang, vu nang, van nang
di ca » di cau, di cua, doi ca

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)) x ho. hieu van cau truc va thanh di ca viet~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ((y nang) OR (v nang)) x ho. hieu van cau truc va thanh di ca viet*".