Perhaps you should try some spelling variations:
nam thuc » nam thuoc, am thuc, nam thu
hoa lang » hoa dan, hoa van
cam thuc » am thuc, cam thu, can thuc
tai cua » thai cua, tai cuc, tri cua
va lang » va nang
te sach » toc sach
sach ty » sach y, sach tu, sach thu
hieu va » lieu va, hieu qua
ty nang » ky nang, ty xang, ty hang
cua tre » cua te, cuu tre, cua triet
x hoi » xa hoi, o hoi, x ho

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 ty nang x hoi. hieu va ((cam thuc) OR (nam thuc)) ((va lang) or (hoa lang)) tai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ty nang x hoi. hieu va ((cam thuc) OR (nam thuc)) ((va lang) OR (hoa lang)) tai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ty nang x hoi. hieu va ((cam thuc) OR (nam thuc)) ((va lang) or (hoa lang)) tai cua tre".
• Adding a wildcard symbol may retrieve word variants: te sach ty nang x hoi. hieu va ((cam thuc) OR (nam thuc)) ((va lang) or (hoa lang)) tai cua tre*.