Perhaps you should try some spelling variations:
tru nang » tra nang, tri nang, truc nano
thi nang » thi cong, ki nang, thi hanh
hieu van » hieu va, thien van, lieu va
tu sach » thu sach, su sach, te sach
hang di » hang doi, hang vi, hang dien
hanh di » hanh vi, hanh de, danh di
van cam » van nam, van lam, van cau
cam cua » ca cua, nam cua, cau cua
cua tre » cua te, cuu tre, cua triet

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 ((tru nang) or (thi nang)) xa hoi. hieu van cam cua ban ((hanh di) OR (hang di)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((tru nang) OR (thi nang)) xa hoi. hieu van cam cua ban ((hanh di) OR (hang di)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ((tru nang) or (thi nang)) xa hoi. hieu van cam cua ban ((hanh di) OR (hang di)) cua tre".
• Adding a wildcard symbol may retrieve word variants: tu sach ((tru nang) or (thi nang)) xa hoi. hieu van cam cua ban ((hanh di) OR (hang di)) cua tre*.