Perhaps you should try some spelling variations:
tham thuc » nham thuc, pham thuc, tam thuc
dang thai » dang thi, dang hai, dang khai
dang tai » dung tai, hang tai, dang thi
va tham » van tham, va cham, va thanh
van tai » von tai, van tuan
han tai » hang tai, nhan tai, toan tai
thuc va » thuc vat, thuc dan, thuc day
te sach » toc sach
hieu va » lieu va, hieu qua
sach ky » sac ky, sach y, sach ty
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 tai) OR (dang thai)) chi. hieu va tham thuc va ((han tai) or (van tai)) cuc tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ky ((dang tai) OR (dang thai)) chi. hieu va tham thuc va ((han tai) OR (van tai)) cuc tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ky ((dang tai) OR (dang thai)) chi. hieu va tham thuc va ((han tai) or (van tai)) cuc tre".
• Adding a wildcard symbol may retrieve word variants: te sach ky ((dang tai) OR (dang thai)) chi. hieu va tham thuc va ((han tai) or (van tai)) cuc tre*.