Perhaps you should try some spelling variations:
lang man » lang van, lang ban, dang manh
hanh vai » hanh vi, hanh tai, hanh van
lang mai » lang dai, lang hai, sang mai
tu sach » thu sach, su sach, te sach
hanh va » hang va, hanh vi
va cham » va chat, va tham
hieu va » lieu va, hieu qua
cu tren » tu tren, dua tren
soc va » hoc va, loc va, doc va

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 _ ((lang man) OR (lang mai)) khoi. hieu va cham soc va ((hanh vai) or (hanh va)) cu tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach _ ((lang man) OR (lang mai)) khoi. hieu va cham soc va ((hanh vai) OR (hanh va)) cu tren.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach _ ((lang man) OR (lang mai)) khoi. hieu va cham soc va ((hanh vai) or (hanh va)) cu tren".
• Adding a wildcard symbol may retrieve word variants: tu sach _ ((lang man) OR (lang mai)) khoi. hieu va cham soc va ((hanh vai) or (hanh va)) cu tren*.