Perhaps you should try some spelling variations:
thu sach » thuat sach, thuoc sach, thu hoach
tinh dan » trinh dan, tinh da, binh dan
cam truc » cau truc, nam truc, lam truoc
nang cam » nang cham, nang cao, nang cap
va tinh » may tinh
truc va » thuc va, thuc vat, trung va
ca tren » cau tren, cu tren, la tren
tu sach » su sach, te sach, tu cach
ma hoi » mai hoi, ma hoa, me hoi

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)) ky nang ((ma hoi) OR (xa hoi)). ki nang cam truc va tinh dan ca tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((thu sach) OR (tu sach)) ky nang ((ma hoi) OR (xa hoi)). ki nang cam truc va tinh dan ca tren.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((thu sach) or (tu sach)) ky nang ((ma hoi) OR (xa hoi)). ki nang cam truc va tinh dan ca tren".
• Adding a wildcard symbol may retrieve word variants: ((thu sach) or (tu sach)) ky nang ((ma hoi) OR (xa hoi)). ki nang cam truc va tinh dan ca tren*.