Perhaps you should try some spelling variations:
hieu viec » nhieu viec, hieu ve, sieu viet
thu sach » tu sach, thuat sach, thuoc sach
dai nuoc » dat nuoc, dau nuoc, dai luoc
viec dai » vien dai, viec tai, viec dat
hanh va » hang va, hanh vi
va hanh » van hanh, va thanh, va danh
mai hoi » mai khoi, dai hoi, lai hoi
ky tang » ky nang, ky dang, kho tang
ky lang » ky nang, ky dang, tay lang
hoc cac » hoc cao
va cua » va chua, via cua, ca cua
cua te » cua tu

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((thu sach) or (hoc cac)) ((ky lang) OR (ky tang)) mai hoi. hieu viec dai nuoc va hanh va cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((thu sach) OR (hoc cac)) ((ky lang) OR (ky tang)) mai hoi. hieu viec dai nuoc va hanh va cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((thu sach) or (hoc cac)) ((ky lang) OR (ky tang)) mai hoi. hieu viec dai nuoc va hanh va cua te".
• Adding a wildcard symbol may retrieve word variants: ((thu sach) or (hoc cac)) ((ky lang) OR (ky tang)) mai hoi. hieu viec dai nuoc va hanh va cua te*.