Perhaps you should try some spelling variations:
thanh vai » thanh hai, thanh van, thanh tai
van thanh » ban thanh, van tuan
cua quoc » cua nuoc, cua thuoc
nang mai » nang ma, nang tai, lang mai
mai khoi » mai khoa, tai khoa, cac khoi
vai cua » dai cua, hai cua, lai cua
tu sach » thu sach, su sach, te sach
hieu va » lieu va, hieu qua
y nang » ky nang, ly nang, v nang

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