Perhaps you should try some spelling variations:
"tu sach kxmky thuat o khi" » "tu sach kxy thuat o khi", "thu sach kxmky thuat o khi", "tu cach kxmky thuat o khi", "vu sach kxmky thuat o khi", "tu sach kxmky thuat do khi", "tu sach kxmky thuat bo khi"
"su sach ky thuat bao chi" » "su sach ky thuat bai chi", "su sach ky thuat giao chi", "su sach ky thuat do chi", "su sac ky thuat bao chi", "su sach y thuat bao chi", "su sach ty thuat bao chi", "so sach ky thuat bao chi", "vu sach ky thuat bao chi", "su sach ky thuat bao che"
"te sach ky thuat co khi" » "te sach ky thuat do khi", "toc sach ky thuat co khi", "te sac ky thuat co khi", "te sach y thuat co khi", "te sach ty thuat co khi", "te sach ky thuat cbo khi"

Try widening your search to All Fields.

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 ky thuat co khi") or ((("su sach ky thuat bao chi") or ("tu sach kxmky thuat o khi"))))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("te sach ky thuat co khi") OR ((("su sach ky thuat bao chi") OR ("tu sach kxmky thuat o khi")))).
• Removing quotes may allow a broader search: (( te sach ky thuat co khi ) or ((( su sach ky thuat bao chi ) or ( tu sach kxmky thuat o khi )))).
• Adding a wildcard symbol may retrieve word variants: (("te sach ky thuat co khi") or ((("su sach ky thuat bao chi") or ("tu sach kxmky thuat o khi"))))*.