Canvasing and leafleting continued in Boston yesterday as students sought mass disapproval of President Nixon's policies in Southeast Asia from the public and businesses.

In the Harvard Square area. 56 store owners followed the recommendation of the Harvard Square Business Association and will close their doors between 3 and 5 p..m. today to "display their solidarity against action in Cambodia."

Boston Colleges

At least 30 Boston-area colleges and universities were on strike yesterday with many campuses suspending academic activities for an indefinite period.

Only Boston University. however, has shut down for the remainder of the school year. To avoid possible student troubles, the B.U. administration postponed until next Wednesday its plans to close dormitories yesterday at 5 p.m.

Canvassing

Nearly 300 students canvassed city wards four and 15 and the ninth Congressional district. asking people to sign petitions and write their Congressmen against the Cambodian situation. Workers found that only 30 per cent of the residents were home and emphasized the need to continue canvassing during the weekend.

Students also leafleted some 20 factories and post offices in Boston early yesterday morning and received a positive reaction from most workers, according to the M.I.T. information center.

Twenty-eight telegram stations in Boston reported that 7000 telegrams were sent to Congressmen and Senators from people solicited at these booths. The booths covered all of Boston, particularly large subway stops and shopping centers.

"These telegram stations have been vital not only in sending telegrams." said Elaine Sherman at the M.I.T. regional strike headquarters, "but also have served as the focal point for public discussions."

High schools were also a target for leaf letlers and students at 18 area schools have said they will strike today to participate in Friday's demonstration at Harvard. Watertown High School received the first parade permit everissued in that town and will march to Soldiers Field today.

Businesses

Businesses will also join in tomorrow's rally. Nearly 200 employees of Houghton- Mifllin Publishing Company will march from the Boston Common and join the march to Harvard. Little Brown Co. will also send employees to the rally.

An open meeting of the House Officers Association of Boston City Hospital voted to endorse the national student strike and demanded immediate withdrawal of troops from Southeast Asia. about 400 residents and interns at the Hospital backed all student demands and will participate in the activities today.