Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
va tham » van tham, va cham, va thanh
va dinh » van dinh, va kinh, va tinh
thuc va » thuc vat, thuc dan, thuc day
sach ty » sach y, sach tu, sach thu
va nham » va cham, va nha, va kham
nang ma » tang ma, sang ma, nang cao
ty nang » ky nang, ty xang, ty hang
ma hoi » mai hoi, xa hoi, ma hoa
di cua » doi cua, de cua, do cua

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 ty nang ma hoi. lieu ((va nham) OR (va tham)) thuc va dinh ((di cua) or (dai cua)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ty nang ma hoi. lieu ((va nham) OR (va tham)) thuc va dinh ((di cua) OR (dai cua)) tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach ty nang ma hoi. lieu ((va nham) OR (va tham)) thuc va dinh ((di cua) or (dai cua)) tre".
• Adding a wildcard symbol may retrieve word variants: toc sach ty nang ma hoi. lieu ((va nham) OR (va tham)) thuc va dinh ((di cua) or (dai cua)) tre*.