Perhaps you should try some spelling variations:
sach hay » sach han, sach ha, sach nay
hoang xa » hoang ha, hoang va, hoang xuan
sach ty » sach y, sach tu, sach thu
hieu va » lieu va, hieu qua
cac luc » cau luc, coc luc, cac nuoc
va hanh » van hanh, va thanh, va danh
vai cua » dai cua, hai cua, lai cua
luc va » duc va, tuc va, loc va
vi cua » di cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: thuat ((sach hay) or (sach ty)) hoang xa hoi. hieu va cac luc va hanh ((vi cua) OR (vai cua)) tu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuat ((sach hay) OR (sach ty)) hoang xa hoi. hieu va cac luc va hanh ((vi cua) OR (vai cua)) tu.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thuat ((sach hay) or (sach ty)) hoang xa hoi. hieu va cac luc va hanh ((vi cua) OR (vai cua)) tu".
• Adding a wildcard symbol may retrieve word variants: thuat ((sach hay) or (sach ty)) hoang xa hoi. hieu va cac luc va hanh ((vi cua) OR (vai cua)) tu*.