Perhaps you should try some spelling variations:
tham thuc » nham thuc, pham thuc, tam thuc
vanh dai » van dai, vanh tai, lanh dao
hanh dai » hanh tai, hanh dao, thanh dat
tao khoi » tao hoi, thao khoa, lao khoa
thuc van » thuc vat, thuc dan, thuc va
su sach » so sach, vu sach
ve tham » va tham, ve cham, vi tham
tai hoi » tai khoi, dai hoi, tai hai
hieu ve » hieu va, hieu van
y nang » ky nang, ly nang, v nang
cua te » cua tu

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 y nang ((tai hoi) or (tao khoi)). hieu ve tham thuc van ((hanh dai) OR (vanh dai)) cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach y nang ((tai hoi) OR (tao khoi)). hieu ve tham thuc van ((hanh dai) OR (vanh dai)) cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach y nang ((tai hoi) or (tao khoi)). hieu ve tham thuc van ((hanh dai) OR (vanh dai)) cua te".
• Adding a wildcard symbol may retrieve word variants: su sach y nang ((tai hoi) or (tao khoi)). hieu ve tham thuc van ((hanh dai) OR (vanh dai)) cua te*.