Perhaps you should try some spelling variations:
thanh dai » thanh hai, thanh tai, thanh dat
thu sach » thuat sach, thuoc sach, thu hoach
nang mai » nang ma, nang tai, lang mai
cua quoc » cua nuoc, cua thuoc
tu sach » su sach, te sach, tu cach
mai hoi » mai khoi, dai hoi, lai hoi
qua cam » qua cham, qua cac, qua ca
xuc van » luc van, vuc van, xuc ban
duc van » duc va, duc tan, duc manh

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) or (thu sach)) ky nang mai hoi. hieu qua cam ((xuc van) OR (duc van)) thanh dai cua quoc~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (thu sach)) ky nang mai hoi. hieu qua cam ((xuc van) OR (duc van)) thanh dai cua quoc.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) or (thu sach)) ky nang mai hoi. hieu qua cam ((xuc van) OR (duc van)) thanh dai cua quoc".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (thu sach)) ky nang mai hoi. hieu qua cam ((xuc van) OR (duc van)) thanh dai cua quoc*.