Perhaps you should try some spelling variations:
hoc sach » hoc sinh, hoc cac, hoc anh
van hanh » van thanh, van anh, van ban
ban hanh » ban hang
cau tren » cu tren, dau tren, ca tren
hieu va » lieu va, hieu qua
cam tuc » cam xuc, cam tu, nam thuc
sach ty » sach y, sach tu, sach thu
nang xa » nang x, lang xa, nang ma
ty nang » ky nang, ty xang, ty hang
cuu tre » cua tre, cau treo
va cam » va cham, va cac, va cao

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc sach ty nang xa hoi. hieu va cam tuc ((van hanh) OR (ban hanh)) vi ((cuu tre) or (cau tren))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc sach ty nang xa hoi. hieu va cam tuc ((van hanh) OR (ban hanh)) vi ((cuu tre) OR (cau tren)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc sach ty nang xa hoi. hieu va cam tuc ((van hanh) OR (ban hanh)) vi ((cuu tre) or (cau tren))".
• Adding a wildcard symbol may retrieve word variants: hoc sach ty nang xa hoi. hieu va cam tuc ((van hanh) OR (ban hanh)) vi ((cuu tre) or (cau tren))*.