Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
hanh vai » hanh vi, hanh tai, hanh van
cau tren » cu tren, dau tren, ca tren
lang mai » lang dai, lang hai, lang man
mai khoi » mai khoa, tai khoa, cac khoi
hieu ve » hieu van
hieu va » lieu va, hieu qua
hanh va » hang va, hanh vi
y lang » o lang, _ lang, tay lang
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: thu sach y lang mai khoi. ((hieu ve) OR (hieu va)) cham soc va ((hanh vai) or (hanh va)) cau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach y lang mai khoi. ((hieu ve) OR (hieu va)) cham soc va ((hanh vai) OR (hanh va)) cau tren.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach y lang mai khoi. ((hieu ve) OR (hieu va)) cham soc va ((hanh vai) or (hanh va)) cau tren".
• Adding a wildcard symbol may retrieve word variants: thu sach y lang mai khoi. ((hieu ve) OR (hieu va)) cham soc va ((hanh vai) or (hanh va)) cau tren*.