Perhaps you should try some spelling variations:
tham thuc » nham thuc, pham thuc, tam thuc
cau treo » cau theo, cau tren, cau triet
vat danh » va danh, van danh, luat danh
sach ky » sac ky, sach y, sach ty
cuu tre » cua tre, cau tren
danh vi » hanh vi, dinh vi, danh di
su sach » so sach, vu sach
hieu va » lieu va, hieu qua
tang ma » mang may, tang van
va tham » van tham, va cham, va thanh

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 ((nang x) or (tang ma)) hoi. hieu va tham thuc vat danh vi ((cuu tre) OR (cau treo))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky ((nang x) OR (tang ma)) hoi. hieu va tham thuc vat danh vi ((cuu tre) OR (cau treo)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ky ((nang x) or (tang ma)) hoi. hieu va tham thuc vat danh vi ((cuu tre) OR (cau treo))".
• Adding a wildcard symbol may retrieve word variants: su sach ky ((nang x) or (tang ma)) hoi. hieu va tham thuc vat danh vi ((cuu tre) OR (cau treo))*.