Perhaps you should try some spelling variations:
luoc dai » cuoc doi, hoc dai, duc dai
sang lao » sang tao, sang lap, tang lao
lao khoa » lo khoa, da khoa, ly khoa
cua tre » cua te, cuu tre, cua triet
ky sang » ky nang, ky dang, ky tang
hanh di » hanh vi, hanh de, hang di
duc van » duc va, duc tan, duc manh
di cua » dai cua, doi cua, de cua
te sac » te sach, te cac, te san
sac ky » cac ky, sai ky
ve cac » vien cac

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

• Performing a fuzzy search may retrieve terms with similar spellings: te sac ky sang lao khoa. hieu ((ve cac) OR (va cac)) ((duc van) or (luoc dai)) hanh di cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sac ky sang lao khoa. hieu ((ve cac) OR (va cac)) ((duc van) OR (luoc dai)) hanh di cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sac ky sang lao khoa. hieu ((ve cac) OR (va cac)) ((duc van) or (luoc dai)) hanh di cua tre".
• Adding a wildcard symbol may retrieve word variants: te sac ky sang lao khoa. hieu ((ve cac) OR (va cac)) ((duc van) or (luoc dai)) hanh di cua tre*.