Perhaps you should try some spelling variations:
tham thuc » nham thuc, pham thuc, tam thuc
dang bai » dung bai, dang hai, dang ba
van tuan » van quan, van ban, anh tuan
thuc va » thuc vat, thuc dan, thuc day
van tai » von tai
han tai » hang tai, nhan tai, toan tai
te sach » toc sach
sach ky » sac ky, sach y, sach ty
va tham » van tham, va cham, va thanh
hieu va » lieu va, hieu qua
bai hoc » dai hoc
ky dang » ky nang, ky danh
cuc tre » duc tre, cua tre, cuu tre

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

• Performing a fuzzy search may retrieve terms with similar spellings: te sach ky dang bai hoc. hieu va tham thuc va ((han tai) or (((van tai) OR (van tuan)))) cuc tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ky dang bai hoc. hieu va tham thuc va ((han tai) OR (((van tai) OR (van tuan)))) cuc tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ky dang bai hoc. hieu va tham thuc va ((han tai) or (((van tai) OR (van tuan)))) cuc tre".
• Adding a wildcard symbol may retrieve word variants: te sach ky dang bai hoc. hieu va tham thuc va ((han tai) or (((van tai) OR (van tuan)))) cuc tre*.