Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
thuc van » thuc vat, thuc dan, thuc va
nang hoc » nang doc, nang luc, dong hoc
sach ky » sach y, sach ty, sach kem
kem cua » em cua, keo cua, diem cua
cua tre » cua te, cuu tre, cua triet
hoc hoi » hoc khoi, hoc hoa, hoc noi
ve cac » va cac, vien cac
sac ky » cac ky, sai ky
ve cam » ve cham, va cam, ve cai

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu ((sach ky) or (sac ky)) nang hoc hoi. hieu ((ve cam) or (ve cac)) thuc van hanh kem cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach ky) OR (sac ky)) nang hoc hoi. hieu ((ve cam) OR (ve cac)) thuc van hanh kem cua tre.
• Adding a wildcard symbol may retrieve word variants: tu ((sach ky) or (sac ky)) nang hoc hoi. hieu ((ve cam) or (ve cac)) thuc van hanh kem cua tre*.