Perhaps you should try some spelling variations:
va thanh » gia thanh, ban thanh, va tinh
va hanh » van hanh, va danh, ban hanh
sach ty » sach tu, sach thu, xach tay
nang xa » nang x, lang xa, nang ma
hieu va » lieu va, hieu qua
nam xua » nam cua, nam mua, nam qua
va nam » van nam, ha nam, va nay
vi cua » vai cua, di cua

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) or (sach ty)) nang xa hoi. hieu va nam xua ((va hanh) or (va thanh)) vi cua vat~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su ((sach y) OR (sach ty)) nang xa hoi. hieu va nam xua ((va hanh) OR (va thanh)) vi cua vat.
• Adding a wildcard symbol may retrieve word variants: su ((sach y) or (sach ty)) nang xa hoi. hieu va nam xua ((va hanh) or (va thanh)) vi cua vat*.