Perhaps you should try some spelling variations:
"tu sach ki thuat do thi" » "tu sach ki thuat o thi", "tu sach kinh thuat do thi", "tu sach bai thuat do thi", "tu sach kem thuat do thi", "thu sach ki thuat do thi", "su sach ki thuat do thi", "tu cach ki thuat do thi"
"hoc sach ky thuat bo chi" » "hoc sinh ky thuat bo chi", "hoc cac ky thuat bo chi", "hoc anh ky thuat bo chi", "hoc sach ky thuat bao chi", "hoc sach ky thuat o chi", "hoc sach ky thuat co chi", "hoc sac ky thuat bo chi", "hoc sach y thuat bo chi", "hoc sach kem thuat bo chi", "hoc sach ky thuat ho chi", "hoc sach ky thuat bo cai"
"te sach ty thua bo khi" » "te sach y thua bo khi", "te sach tu thua bo khi", "te sach thu thua bo khi", "toc sach ty thua bo khi", "te sach ty thuat bao khi", "te sach ty thuat co khi", "te sach ty thuat so khi", "te sach ky thua bo khi", "te sach ty nhua bo khi", "te sach ty thua co khi", "te sach ty thua bo thi"

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: (((("te sach ty thua bo khi") or ("hoc sach ky thuat bo chi"))) or ("tu sach ki thuat do thi"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("te sach ty thua bo khi") OR ("hoc sach ky thuat bo chi"))) OR ("tu sach ki thuat do thi")).
• Removing quotes may allow a broader search: (((( te sach ty thua bo khi ) or ( hoc sach ky thuat bo chi ))) or ( tu sach ki thuat do thi )).
• Adding a wildcard symbol may retrieve word variants: (((("te sach ty thua bo khi") or ("hoc sach ky thuat bo chi"))) or ("tu sach ki thuat do thi"))*.