Perhaps you should try some spelling variations:
thuoc sach » thuat sach, thuoc sinh, toc sach
nuoc sach » nguoi sach, cuoc cach, cuon sach
kxy thuat » ky thuat, ki thuat, my thuat
thu sach » tu sach, thuat sach, thu hoach
hoc sach » hoc sinh, hoc cac, hoc anh
thuat do » thuat o
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: ((thu sach) or (((((thuoc sach) OR (nuoc sach))) or (hoc sach)))) kxy thuat do khi~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((thu sach) OR (((((thuoc sach) OR (nuoc sach))) OR (hoc sach)))) kxy thuat do khi.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((thu sach) or (((((thuoc sach) OR (nuoc sach))) or (hoc sach)))) kxy thuat do khi".
• Adding a wildcard symbol may retrieve word variants: ((thu sach) or (((((thuoc sach) OR (nuoc sach))) or (hoc sach)))) kxy thuat do khi*.