Perhaps you should try some spelling variations:
nang cho » nang chon, ngang cho, nang cao
hieu van » hieu va, thien van, lieu va
cau tren » cu tren, dau tren, ca tren
tu sach » thu sach, su sach, te sach
sach ty » sach y, sach tu, sach thu
ty nang » ky nang, ty xang, ty hang
cho hoc » co hoc, khoa hoc
van cam » van nam, van lam, van cau
truc va » thuc va, thuc vat, trung va
tuc va » thuc va, tuc xa, duc va
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: tu sach ty nang cho hoc. hieu van cam ((tuc va) or (truc va)) dan ca cau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ty nang cho hoc. hieu van cam ((tuc va) OR (truc va)) dan ca cau tren.
• Adding a wildcard symbol may retrieve word variants: tu sach ty nang cho hoc. hieu van cam ((tuc va) or (truc va)) dan ca cau tren*.