Perhaps you should try some spelling variations:
hieu quan » hieu qua, lieu quan, thien quan
quan cau » quang cao, toan cau, quan ha
cau thuc » cau truc, cuu thuc, can thuc
vat hanh » vat thanh, van hanh, va hanh
cau tren » cu tren, dau tren, ca tren
su sach » vu sach
so sach » so sanh, bo sach, co sach
ky lang » ky nang, ky dang, ky tang
lang xa » lang ha, dang xay, lang van
hanh va » hang va, hanh vi
va cau » van cau, va cac, va dau

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((su sach) OR (so sach)) ky lang xa hoi. hieu quan cau thuc vat hanh va cau tren~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((su sach) OR (so sach)) ky lang xa hoi. hieu quan cau thuc vat hanh va cau tren".
• Adding a wildcard symbol may retrieve word variants: ((su sach) OR (so sach)) ky lang xa hoi. hieu quan cau thuc vat hanh va cau tren*.