Perhaps you should try some spelling variations:
sach trien » sach tien, sach tren, sach thieu
trien khai » trien nha
nhan chan » nhan chat, nhan nhanh, khang chan
khai khoa » thai khoa, chai khoa, khat khoa
toc sach » hoc sach, doc sach, thuoc sach
nha chai » nhan chat, nha cao, nha ha
khoa hoc » hoa hoc
tu sach » thu sach, su sach, te sach

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( toc sach ((nha chai) OR (nhan chan)) khoa hoc ) or ( tu sach trien khai khoa hoc ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( toc sach ((nha chai) OR (nhan chan)) khoa hoc ) OR ( tu sach trien khai khoa hoc ))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( toc sach ((nha chai) OR (nhan chan)) khoa hoc ) or ( tu sach trien khai khoa hoc ))*".