Below is the list of tables from the database along with their columns and datatype. Need to generate an accurate SQL query for the question.
Only use the columns present in the respective table. Only use the columns which are required to generate the SQL query. Only use table joins if required and not otherwise.

### Tables ###
TABLE: CREATE TABLE table_name_51 (crude_death_rate__per_1000_ INTEGER, deaths VARCHAR, crude_birth_rate__per_1000_ VARCHAR)

### Question ###
Which Crude death rate (per 1000) has Deaths of 768, and a Crude birth rate (per 1000) smaller than 29.7?

### Accurate SQL ###

SELECT MIN(crude_death_rate__per_1000_) FROM table_name_51 WHERE deaths = "768" AND crude_birth_rate__per_1000_ < 29.7