Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
nang cau » nang cao, hang cau, nang dau
hieu van » hieu va, thien van, lieu va
nam thuc » nam thuoc, am thuc, nam thu
cau tren » cu tren, dau tren, ca tren
te sach » toc sach
thuc ca » thuc cua, thuc can, thuc cao
ca dan » cac dan, ca dao
ca cau » cua cau, cac cau, can cau

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) or (thu sach)) ky nang cau hoi. hieu van nam thuc ca dan ca cau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sach) OR (thu sach)) ky nang cau hoi. hieu van nam thuc ca dan ca cau tren.
• Adding a wildcard symbol may retrieve word variants: ((te sach) or (thu sach)) ky nang cau hoi. hieu van nam thuc ca dan ca cau tren*.