Perhaps you should try some spelling variations:
thu sach » thuat sach, thuoc sach, thu hoach
han thai » han tai, ban thai, van thai
tu sach » su sach, te sach, tu cach
nang xa » nang x, lang xa, nang ma
hieu va » lieu va, hieu qua
va cham » va chat, va tham
thai va » thai van
y nang » ky nang, ly nang, v nang
xuc va » tuc va, luc va, xac va
thiet » thieu

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) OR (tu sach)) y nang xa hoi. hieu va cham ((xuc va) or (duc va)) han thai va thiet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((thu sach) OR (tu sach)) y nang xa hoi. hieu va cham ((xuc va) OR (duc va)) han thai va thiet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((thu sach) OR (tu sach)) y nang xa hoi. hieu va cham ((xuc va) or (duc va)) han thai va thiet".
• Adding a wildcard symbol may retrieve word variants: ((thu sach) OR (tu sach)) y nang xa hoi. hieu va cham ((xuc va) or (duc va)) han thai va thiet*.