Perhaps you should try some spelling variations:
viec cac » vien cac, viec lam, viec va
su sach » so sach, vu sach
ly nang » ky nang, ly hang, ly vang
cao hoa » cao hoat, cao khoa, cau hoa
va hang » van hang, va nang, va lang
cua tre » cua te, cuu tre, cua triet
y nang » ky nang, v nang, may nang
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: su sach ((y nang) OR (ly nang)) cao hoa. hieu ((viec cac) or (viec cua)) tu va hang va cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ((y nang) OR (ly nang)) cao hoa. hieu ((viec cac) OR (viec cua)) tu va hang va cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ((y nang) OR (ly nang)) cao hoa. hieu ((viec cac) or (viec cua)) tu va hang va cua tre".
• Adding a wildcard symbol may retrieve word variants: su sach ((y nang) OR (ly nang)) cao hoa. hieu ((viec cac) or (viec cua)) tu va hang va cua tre*.