Perhaps you should try some spelling variations:
pho thong » he thong
thuat may » thuat xay, thuat gay, thuat bai
hoc bach » hoc sach, hoc cach, hoc bac
sach dao » lanh dao
khoa pho » khoa phu, khoa khoa, khoa phau
may khoa » da khoa, ly khoa, y khoa
ki thuat » ky thuat
sach ki » sach kinh, sach bai, sach kem
dao hoc » dai hoc, dan hoc, day hoc
tu sach » thu sach, su sach, te sach
va thu » va thuc, van thu, va tu

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 ki thuat may khoa pho thong ) or ( tu sach dao hoc bach ((ma thu) OR (va thu)) thang ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( tu sach ki thuat may khoa pho thong ) OR ( tu sach dao hoc bach ((ma thu) OR (va thu)) thang )).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( tu sach ki thuat may khoa pho thong ) or ( tu sach dao hoc bach ((ma thu) OR (va thu)) thang ))".
• Adding a wildcard symbol may retrieve word variants: (( tu sach ki thuat may khoa pho thong ) or ( tu sach dao hoc bach ((ma thu) OR (va thu)) thang ))*.