Perhaps you should try some spelling variations:
hoc truc » hoc thuc, hoc trung, hoc thuoc
thai cua » than cua, tai cuc, tri cua
hieu van » hieu va, thien van, lieu va
hau truc » cau truc, hang truc, tu truc
va thanh » ban thanh, va tinh, le thanh
tu sach » thu sach, su sach, te sach
cua tre » cua te, cuu tre, cua triet
nang xa » nang x, lang xa, nang ma
y nang » ky nang, ly nang, v nang

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 y nang xa hoi. hieu van ((hau truc) OR (hoc truc)) ((va thanh) or (gia thanh)) thai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach y nang xa hoi. hieu van ((hau truc) OR (hoc truc)) ((va thanh) OR (gia thanh)) thai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach y nang xa hoi. hieu van ((hau truc) OR (hoc truc)) ((va thanh) or (gia thanh)) thai cua tre".
• Adding a wildcard symbol may retrieve word variants: tu sach y nang xa hoi. hieu van ((hau truc) OR (hoc truc)) ((va thanh) or (gia thanh)) thai cua tre*.