Perhaps you should try some spelling variations:
tham thuc » nham thuc, pham thuc, tam thuc
su sach » so sach, vu sach
luu tre » cuu tre, luy tre
danh vi » hanh vi, dinh vi, danh di
va danh » va dinh, va dan, va hanh
thuc va » thuc vat, thuc dan, thuc day
va tham » van tham, va cham, va thanh
sach ky » sac ky, sach y, sach ty
hieu va » lieu va, hieu qua
tang ma » mang may, tang van
tru » truc

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 va danh vi ((luu tre) OR (luu tru))~.
• 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 va danh vi ((luu tre) OR (luu tru)).
• 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 va danh vi ((luu tre) OR (luu tru))".
• Adding a wildcard symbol may retrieve word variants: su sach ky ((nang x) or (tang ma)) hoi. hieu va tham thuc va danh vi ((luu tre) OR (luu tru))*.