Perhaps you should try some spelling variations:
thu sach » thuat sach, thuoc sach, thu hoach
van hanh » van thanh, ban hanh, van anh
cham loc » cham soc, chon loc, cham o
tu sach » su sach, te sach, tu cach
hanh va » hang va, hanh vi
loc van » luoc van, hoc van, lo van
ve cham » va cham, ve chat, vu cham
hieu ve » hieu va, hieu van
cua tre » cua te, cuu tre, cua triet
ty nang » ky nang, ty xang, ty hang
ma hoi » mai hoi, ma hoa, me hoi
va cua » va chua, via cua, ca cua

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) or (thu sach)) ty nang ((ma hoi) or (xa hoi)). hieu ve cham loc van hanh va cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (thu sach)) ty nang ((ma hoi) OR (xa hoi)). hieu ve cham loc van hanh va cua tre.
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (thu sach)) ty nang ((ma hoi) or (xa hoi)). hieu ve cham loc van hanh va cua tre*.