Perhaps you should try some spelling variations:
cham duc » pham duc, cham soc, pham duy
thu sach » thuat sach, thuoc sach, thu hoach
van hanh » van thanh, ban hanh, van anh
sang lao » sang tao, sang lap, tang lao
lao khoa » lo khoa, da khoa, ly khoa
tu sach » su sach, te sach, tu cach
lai cua » dai cua, hai cua, lai chau
va hanh » va thanh, va danh, ban hanh
hieu vu » hieu va, hieu ve, hieu su
vu cham » va cham, vu kham, tu cham
ty sang » ty xang, ty hang, duy sang
cua tre » cua te, cuu tre, cua triet

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 sang lao khoa. hieu vu cham duc ((va hanh) or (van hanh)) lai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (thu sach)) ty sang lao khoa. hieu vu cham duc ((va hanh) OR (van hanh)) lai cua tre.
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (thu sach)) ty sang lao khoa. hieu vu cham duc ((va hanh) or (van hanh)) lai cua tre*.