Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
hieu van » hieu va, thien van, lieu va
ly nang » ky nang, ly hang, ly vang
van cam » van nam, van lam, van cau
cam duc » cam xuc, cao duc, pham duc
y nang » ky nang, v nang, may nang
va don » va dong, va doc, va do
cua tu » cua tuc, cua su, cua cu

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

• Performing a fuzzy search may retrieve terms with similar spellings: thu sach ((y nang) or (ly nang)) ma hoa. hieu van cam duc va don vi ((cua te) OR (cua tu))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ((y nang) OR (ly nang)) ma hoa. hieu van cam duc va don vi ((cua te) OR (cua tu)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach ((y nang) or (ly nang)) ma hoa. hieu van cam duc va don vi ((cua te) OR (cua tu))".
• Adding a wildcard symbol may retrieve word variants: thu sach ((y nang) or (ly nang)) ma hoa. hieu van cam duc va don vi ((cua te) OR (cua tu))*.