Perhaps you should try some spelling variations:
su sach » so sach, vu sach
hieu va » lieu va, hieu qua
truc va » thuc va, thuc vat, trung va
va hanh » van hanh, va thanh, va danh
hanh ve » hanh vi, hanh va, hanh kem
so viet » hoc viet
y tang » ky tang, 7 tang, 5 tang
va cau » van cau, va cac, va dau
ve so » ve su, va so, ve co

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 ((y tang) or (6 tang)) ((le hoi) or (ma hoa)). hieu va cau truc va hanh ve so viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ((y tang) OR (6 tang)) ((le hoi) OR (ma hoa)). hieu va cau truc va hanh ve so viet.
• Adding a wildcard symbol may retrieve word variants: su sach ((y tang) or (6 tang)) ((le hoi) or (ma hoa)). hieu va cau truc va hanh ve so viet*.