Perhaps you should try some spelling variations:
thuat sach » thuat lanh, thuat san
thu sach » tu sach, thuoc sach, thu hoach
dinh vai » dinh van, dinh vi, dinh va
dau tren » dau tien, dat tren, dau tieng
ky lang » ky nang, ky tang, tay lang
ky dang » ky nang, ky danh
hieu ve » hieu va, hieu van
va dinh » van dinh, va kinh, va tinh
vai dau » va dau, van dau, xvii dau
ve cam » ve cham, ve cac, va cam
cam o » cham o, cam lo, ca o
o va » do va, so va, co 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) or (thuat sach)) ((ky lang) OR (ky dang)) xa hoi. hieu ve cam o va dinh vai dau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((thu sach) OR (thuat sach)) ((ky lang) OR (ky dang)) xa hoi. hieu ve cam o va dinh vai dau tren.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((thu sach) or (thuat sach)) ((ky lang) OR (ky dang)) xa hoi. hieu ve cam o va dinh vai dau tren".
• Adding a wildcard symbol may retrieve word variants: ((thu sach) or (thuat sach)) ((ky lang) OR (ky dang)) xa hoi. hieu ve cam o va dinh vai dau tren*.