Perhaps you should try some spelling variations:
trinh viet » ninh viet, trinh vat
viet cua » viec cua, viet ca, viet qua
va trinh » van trinh, va tinh, lap trinh
tu sach » thu sach, te sach, tu cach
cua tre » cua te, cuu tre, cua triet
ky dang » ky nang, ky danh
dang ha » dong ha, dung ha, lang ha
su sach » so sach, vu sach
ha hoi » hoa hoi, ha noi, xa hoi
ve cac » va cac, vien cac
xuc va » duc va, tuc va, luc va
ve cam » ve cham, va cam, ve cai

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 (su sach)) ky dang ha hoi. hieu ((ve cam) OR (ve cac)) xuc va trinh viet cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (su sach)) ky dang ha hoi. hieu ((ve cam) OR (ve cac)) xuc va trinh viet cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) or (su sach)) ky dang ha hoi. hieu ((ve cam) OR (ve cac)) xuc va trinh viet cua tre".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (su sach)) ky dang ha hoi. hieu ((ve cam) OR (ve cac)) xuc va trinh viet cua tre*.