Perhaps you should try some spelling variations:
thu sach » thuat sach, thuoc sach, thu hoach
thuat bo » thuat bao, thuat o, thuat co
thuat do » thuat o
tu sach » su sach, te sach, tu cach
bo khi » co khi, bo chi, bo thi
tu sac » tu cac, tu san, tu bac
sac ky » cac ky, sai ky
do khi » doi khi, do thi, co khi

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)) ki thuat bo khi ) or ( tu sac ky thuat do khi ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( ((tu sach) OR (thu sach)) ki thuat bo khi ) OR ( tu sac ky thuat do khi )).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( ((tu sach) OR (thu sach)) ki thuat bo khi ) or ( tu sac ky thuat do khi ))".
• Adding a wildcard symbol may retrieve word variants: (( ((tu sach) OR (thu sach)) ki thuat bo khi ) or ( tu sac ky thuat do khi ))*.