Perhaps you should try some spelling variations:
"so sach mki thuat lo thi" » "so sach ki thuat lo thi", "so sach mi thuat lo thi", "so sach ky thuat lo thi", "so sach moi thuat lo thi", "so bach mai thuat lo thi", "so sach bai thuat lo thi", "so sach mki thuat do thi", "so sach mki thuat so thi", "so sach mki thuat li thi", "so sanh mki thuat lo thi", "bo sach mki thuat lo thi", "co sach mki thuat lo thi", "so sach mki thuat le thi", "so sach mki thuat vo thi"
"thu hoach y thuat co khi" » "thu hoach y thuat do khi", "thu hoach ky thuat co khi", "thu hoach my thuat co khi", "thu hoach kxy thuat co khi", "thu hoach xay thuat co khi", "thu hoach yen thuat co khi", "thu hoach su thuat co khi", "thu hoach y thuat cbo khi"
"tu sach y thuat o khi" » "thu sach y thuat o khi", "su sach y thuat o khi", "te sach y thuat o khi", "tu sach ky thuat o khi", "tu sach my thuat o khi", "tu sach kxy thuat o khi", "tu sach y thuat do khi", "tu sach y thuat bo 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 y thuat o khi") or ("thu hoach y thuat co khi"))) or ("so sach mki thuat lo thi"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("tu sach y thuat o khi") OR ("thu hoach y thuat co khi"))) OR ("so sach mki thuat lo thi")).
• Removing quotes may allow a broader search: (((( tu sach y thuat o khi ) or ( thu hoach y thuat co khi ))) or ( so sach mki thuat lo thi )).
• Adding a wildcard symbol may retrieve word variants: (((("tu sach y thuat o khi") or ("thu hoach y thuat co khi"))) or ("so sach mki thuat lo thi"))*.