Perhaps you should try some spelling variations:
thao khoa » thai khoa, toan khoa, pham khoa
nam thuc » nam thuoc, am thuc, nam thu
tvan tai » toan tai, tan tai, tuan tai
lao khoa » lo khoa, da khoa, ly khoa
su sach » so sach, vu sach
van tai » von tai, van tuan
thuc xa » thuc xay, tuc xa, thuc va
cua tre » cua te, cuu tre, cua triet
ky sang » ky nang, ky dang, ky tang
sach ky » sac ky, sach y, sach ty
va nam » van nam, ha nam, va nay

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 ky sang ((thao khoa) or (lao khoa)). lieu va nam thuc xa ((van tai) or (tvan tai)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky sang ((thao khoa) OR (lao khoa)). lieu va nam thuc xa ((van tai) OR (tvan tai)) cua tre.
• Adding a wildcard symbol may retrieve word variants: su sach ky sang ((thao khoa) or (lao khoa)). lieu va nam thuc xa ((van tai) or (tvan tai)) cua tre*.